Distinct Selection Eligibility and Fixed Prefixes

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This question bank has corresponding bilingual step-by-step derivations. Source candidate and English ai_candidate states are retained. AI review, finite computation and Lean formal proof are labelled separately.

batch-20261011-advance-20261015-r06-permutation-combination-foundations · 2026-10-11 · 100 questions

This English edition is an AI candidate and does not yet have an OCME Atlas (GPT-6) Twin closure receipt.

1. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=0, k=0, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(1, 1, 1, Yes)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (1, 1, 1, Yes).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

2. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=1, k=1, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(1, 1, 1, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (1, 1, 1, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

3. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=20, k=19, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(2432902008176640000, 20, 121645100408832000, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (2432902008176640000, 20, 121645100408832000, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

4. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=4, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(24, 4, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (24, 4, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

5. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=5, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(20, 10, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (20, 10, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

6. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=6, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(120, 20, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (120, 20, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

7. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=7, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(42, 21, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (42, 21, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

8. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=8, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(336, 56, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (336, 56, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

9. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=9, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(72, 36, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (72, 36, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

10. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=10, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(720, 120, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (720, 120, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

11. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=11, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(110, 55, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (110, 55, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

12. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=12, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(1320, 220, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (1320, 220, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

13. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=13, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(156, 78, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (156, 78, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

14. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=14, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(2184, 364, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (2184, 364, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

15. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=15, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(210, 105, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (210, 105, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

16. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=16, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(3360, 560, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (3360, 560, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

17. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=17, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(272, 136, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (272, 136, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

18. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=18, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(4896, 816, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (4896, 816, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

19. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=19, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(342, 171, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (342, 171, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

20. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=20, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(6840, 1140, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (6840, 1140, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

21. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=21, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(420, 210, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (420, 210, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

22. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=22, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(9240, 1540, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (9240, 1540, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

23. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=23, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(506, 253, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (506, 253, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

24. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=24, k=3, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(12144, 2024, 6, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (12144, 2024, 6, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

25. Ordered/Unordered Counts, Factorial, and Empty Selection

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=25, k=2, model=distinct_without_replacement. Give (P(n,k), C(n,k), k!, is k=0?).

View answer and explanation

(600, 300, 2, No)

Compute the unordered count exactly and multiply by the ordering factor for the ordered count; an empty selection and empty ordering each count once. The exact result, retaining the requested order, is (600, 300, 2, No).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-order-factor-triple · candidate

26. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(0)=∅, k=0, candidates=[[], [0], [0, 0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, No, No], [Yes, No, No], [Yes, Yes, No], [Yes, No, No], [[], invalid-selection, invalid-selection], [[], invalid-selection, invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, No, No], [Yes, No, No], [Yes, Yes, No], [Yes, No, No], [[], invalid-selection, invalid-selection], [[], invalid-selection, invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

27. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(4)={0,…,3}, k=2, candidates=[[1, 0], [0, 1], [0, 0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, No], [Yes, Yes, No], [[1, 0], [0, 1], invalid-selection], [[0, 1], [0, 1], invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, No], [Yes, Yes, No], [[1, 0], [0, 1], invalid-selection], [[0, 1], [0, 1], invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

28. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(4)={0,…,3}, k=2, candidates=[[0], [0, 1, 2], [0, 4]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, No, Yes], [Yes, Yes, No], [Yes, Yes, Yes], [No, No, No], [invalid-selection, invalid-selection, invalid-selection], [invalid-selection, invalid-selection, invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, No, Yes], [Yes, Yes, No], [Yes, Yes, Yes], [No, No, No], [invalid-selection, invalid-selection, invalid-selection], [invalid-selection, invalid-selection, invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

29. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0, 1], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [[0, 1], [0, 1], [0, 1]], [[0, 1], [0, 1], [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [[0, 1], [0, 1], [0, 1]], [[0, 1], [0, 1], [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

30. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0, 1], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

31. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 0], [0, 1], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

32. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 8], [0, 1], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [No, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [No, Yes, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [invalid-selection, [0, 1], [0, 1]], [invalid-selection, [0, 1], [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

33. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, No, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, No, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

34. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, No, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, No, Yes], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

35. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 0], [0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, No, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, No, Yes], [Yes, Yes, Yes], [No, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

36. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 8], [0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, No, Yes], [No, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, No, Yes], [No, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

37. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0, 0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

38. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0, 0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, Yes, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

39. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 0], [0, 0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

40. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 8], [0, 0], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [No, Yes, Yes], [Yes, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [No, Yes, Yes], [Yes, No, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

41. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0, 8], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, No, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, No, Yes], [Yes, Yes, Yes], [Yes, No, Yes], [[0, 1], invalid-selection, [0, 1]], [[0, 1], invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

42. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0, 8], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, Yes, Yes], [Yes, No, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, Yes, Yes], [Yes, No, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

43. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 0], [0, 8], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [Yes, No, Yes], [No, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [Yes, No, Yes], [No, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

44. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 8], [0, 8], [0, 1]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, Yes], [No, No, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, Yes], [No, No, Yes], [Yes, Yes, Yes], [No, No, Yes], [invalid-selection, invalid-selection, [0, 1]], [invalid-selection, invalid-selection, [0, 1]]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

45. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0, 1], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, No], [[0, 1], [0, 1], invalid-selection], [[0, 1], [0, 1], invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, Yes, No], [[0, 1], [0, 1], invalid-selection], [[0, 1], [0, 1], invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

46. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0, 1], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, Yes, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, Yes, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

47. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 0], [0, 1], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, No], [Yes, Yes, Yes], [No, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, No], [Yes, Yes, Yes], [No, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

48. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 8], [0, 1], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, Yes, No], [No, Yes, Yes], [Yes, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, Yes, No], [No, Yes, Yes], [Yes, Yes, Yes], [No, Yes, No], [invalid-selection, [0, 1], invalid-selection], [invalid-selection, [0, 1], invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

49. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0, 1], [0], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([Yes, No, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, No], [[0, 1], invalid-selection, invalid-selection], [[0, 1], invalid-selection, invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([Yes, No, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [Yes, No, No], [[0, 1], invalid-selection, invalid-selection], [[0, 1], invalid-selection, invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

50. Candidate Selection Length, Typing, and Distinctness

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. Labels=Fin(8)={0,…,7}, k=2, candidates=[[0], [0], [0]]. Give (length mask, all-labels-in-domain mask, all-distinct mask, full eligibility mask, eligible ordered tuples or invalid-selection, eligible sorted subsets or invalid-selection), preserving candidate order.

View answer and explanation

([No, No, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, No], [invalid-selection, invalid-selection, invalid-selection], [invalid-selection, invalid-selection, invalid-selection])

Check length, typing, and distinctness as separate axes; only an eligible row can produce the ordered tuple and its unordered version. The exact result, retaining the requested order, is ([No, No, No], [Yes, Yes, Yes], [Yes, Yes, Yes], [No, No, No], [invalid-selection, invalid-selection, invalid-selection], [invalid-selection, invalid-selection, invalid-selection]).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-fixed-label-qualification · candidate

51. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=1≥1, k=0, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(1, 0, 1, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (1, 0, 1, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

52. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=3≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(1, 1, 0, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (1, 1, 0, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

53. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=20≥1, k=10, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(184756, 92378, 92378, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (184756, 92378, 92378, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

54. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=6≥1, k=5, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(6, 5, 1, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (6, 5, 1, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

55. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=5≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(10, 4, 6, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (10, 4, 6, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

56. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=6≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(20, 10, 10, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (20, 10, 10, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

57. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=7≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(21, 6, 15, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (21, 6, 15, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

58. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=8≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(56, 21, 35, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (56, 21, 35, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

59. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=9≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(36, 8, 28, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (36, 8, 28, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

60. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=10≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(120, 36, 84, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (120, 36, 84, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

61. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=11≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(55, 10, 45, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (55, 10, 45, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

62. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=12≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(220, 55, 165, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (220, 55, 165, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

63. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=13≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(78, 12, 66, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (78, 12, 66, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

64. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=14≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(364, 78, 286, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (364, 78, 286, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

65. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=15≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(105, 14, 91, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (105, 14, 91, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

66. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=16≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(560, 105, 455, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (560, 105, 455, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

67. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=17≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(136, 16, 120, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (136, 16, 120, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

68. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=18≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(816, 136, 680, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (816, 136, 680, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

69. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=19≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(171, 18, 153, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (171, 18, 153, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

70. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=20≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(1140, 171, 969, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (1140, 171, 969, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

71. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=21≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(210, 20, 190, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (210, 20, 190, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

72. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=22≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(1540, 210, 1330, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (1540, 210, 1330, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

73. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=23≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(253, 22, 231, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (253, 22, 231, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

74. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=24≥1, k=3, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(2024, 253, 1771, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (2024, 253, 1771, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

75. Combinations Including or Excluding a Fixed Existing Label

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=25≥1, k=2, fixed existing label 0. Give (all combinations, combinations containing 0, combinations excluding 0, sum of the two parts minus the whole).

View answer and explanation

(300, 24, 276, 0)

Remove the fixed object and count the two eligible subset sizes separately; k=0 has no selection containing 0. The exact result, retaining the requested order, is (300, 24, 276, 0).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-one-distinguished-counts · candidate

76. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=0, k=0, r=0; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(0, 0, 1, 1, 1/1)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (0, 0, 1, 1, 1/1).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

77. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=4, k=2, r=0; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(4, 2, 12, 12, 1/1)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (4, 2, 12, 12, 1/1).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

78. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=4, k=2, r=2; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(2, 0, 1, 12, 1/12)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (2, 0, 1, 12, 1/12).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

79. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=32, k=32, r=16; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(16, 16, 20922789888000, 263130836933693530167218012160000000, 1/12576278705767096320000)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (16, 16, 20922789888000, 263130836933693530167218012160000000, 1/12576278705767096320000).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

80. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=5, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(4, 2, 12, 60, 1/5)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (4, 2, 12, 60, 1/5).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

81. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=6, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(5, 2, 20, 120, 1/6)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (5, 2, 20, 120, 1/6).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

82. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=7, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(6, 2, 30, 210, 1/7)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (6, 2, 30, 210, 1/7).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

83. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=8, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(7, 2, 42, 336, 1/8)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (7, 2, 42, 336, 1/8).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

84. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=9, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(8, 2, 56, 504, 1/9)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (8, 2, 56, 504, 1/9).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

85. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=10, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(9, 2, 72, 720, 1/10)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (9, 2, 72, 720, 1/10).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

86. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=11, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(10, 2, 90, 990, 1/11)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (10, 2, 90, 990, 1/11).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

87. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=12, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(11, 2, 110, 1320, 1/12)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (11, 2, 110, 1320, 1/12).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

88. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=13, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(12, 2, 132, 1716, 1/13)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (12, 2, 132, 1716, 1/13).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

89. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=14, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(13, 2, 156, 2184, 1/14)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (13, 2, 156, 2184, 1/14).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

90. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=15, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(14, 2, 182, 2730, 1/15)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (14, 2, 182, 2730, 1/15).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

91. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=16, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(15, 2, 210, 3360, 1/16)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (15, 2, 210, 3360, 1/16).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

92. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=17, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(16, 2, 240, 4080, 1/17)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (16, 2, 240, 4080, 1/17).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

93. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=18, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(17, 2, 272, 4896, 1/18)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (17, 2, 272, 4896, 1/18).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

94. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=19, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(18, 2, 306, 5814, 1/19)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (18, 2, 306, 5814, 1/19).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

95. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=20, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(19, 2, 342, 6840, 1/20)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (19, 2, 342, 6840, 1/20).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

96. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=21, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(20, 2, 380, 7980, 1/21)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (20, 2, 380, 7980, 1/21).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

97. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=22, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(21, 2, 420, 9240, 1/22)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (21, 2, 420, 9240, 1/22).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

98. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=23, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(22, 2, 462, 10626, 1/23)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (22, 2, 462, 10626, 1/23).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

99. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=24, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(23, 2, 506, 12144, 1/24)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (23, 2, 506, 12144, 1/24).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

100. Completions after Fixing an Initial Ordered Prefix

Select distinct labeled objects without replacement. Ordered and unordered selections are different; the empty selection counts exactly once, with no circular or indistinguishable-object model. n=25, k=3, r=1; the first r positions use labels 0,…,r−1 in that fixed order, empty if r=0. Give (remaining objects, remaining positions, completion count, full ordered count, completion/full count ratio).

View answer and explanation

(24, 2, 552, 13800, 1/25)

Remove the used objects and filled positions before computing both ordered counts and reducing their ratio; a counting ratio does not automatically assert a probability model. The exact result, retaining the requested order, is (24, 2, 552, 13800, 1/25).

Reviewed step-by-step derivation

Permutations and combinations · qf-density15-selection-forced-initial-order · candidate

Canonical question JSONL · English JSONL · Validation report