Select k=3 objects with order ignored, without replacement or repetition, from n=3 distinct objects. Should the model be a permutation or a combination?
G001 — Select k=3 objects with order ignored, without replacement or repetition, from n=3 distinct objects. Should the model be a permutation or a combination?
Definition and scope
Use the original question domain, assumptions and cited MKO definitions. This item has second-context mathematical and bilingual review, with the model, answer and every arithmetic step independently recomputed from the original parameters; the source question remains a candidate.
source roles = [qf-selection-model-choice, [distinct, k, n, operation, ordered, replacement]]
After
derived = [model_choice, no-invented-domain]
Conditions: none
Keep EACH bank’s keys/operation/domain distinct:LDL/PULSE/function legacy table underscores,TREE full tree_* with its declared domain,and permissive BASE signed without invented op/domain.All arithmetic respects the binary-primitive contract.
Given DISTINCT objects WITHOUT replacement/repetition,ordered=True distinguishes positions and uses permutations;False ignores order and uses combinations.Even when k=0 both counts are1,the MODEL still follows the ORIGINAL ordering premise.This is not probability.
S002 · premise_and_result_audit — Reverse-audit THIS question’s ORIGINAL data,types,roles,complete premises and field order.Do not invert implication or turn finite-table checks into infinite-domain/formal proof.Original Q/English/MKO/AST/status remain unchanged.
S001 · premise_and_result_audit — Reverse-audit THIS question’s ORIGINAL data,types,roles,complete premises and field order.Do not invert implication or turn finite-table checks into infinite-domain/formal proof.Original Q/English/MKO/AST/status remain unchanged.
Result
combination
The full substitutions and premise checks give the original answer; source identity,format and status are unchanged.
This question review and source binding
Review date: 2026-10-26
Original questions, answers, step expressions, numeric ASTs and historical records are retained. Source candidate labels remain historical and are not overwritten as formal proof.