{"schema_version":"ocme-site-results-v1","locale":"en","page_type":"derivations","facts":{"questions":36000,"reviewed":36000,"display_candidates":0,"knowledge":302,"guides":299,"paths":59,"batches":360,"families":1441,"atlas":302,"core":80,"evidence":9,"formal_evidence":5,"formal_subjects":4,"lean_files":6,"lean_toolchain":"leanprover/lean4:v4.30.0","question_state":"candidate","english_state":"ai_candidate","question_Lean":"NOT_RUN","canonical_truth_promotion":false},"filters":{"q":"mko-counting-principle"},"kind":"guides","total":1,"pages":1,"page":1,"entries":[{"id":"derivation-mko-counting-principle-01","title":{"zh-Hant":"基本計數原理：數字互異的三位偶數有幾個","en":"Basic counting principles: how many three-digit even numbers have distinct digits"},"summary":{"zh-Hant":"計算 100 到 999 之間、三個數字兩兩相異的偶數共有幾個。要求：只把互斥的類別相加；每次相乘之前，先確認每個階段的可選數對所有先前選擇都相同，不同時先分支。","en":"Count the even integers from 100 to 999 whose three digits are pairwise distinct. Requirements: add only disjoint classes, and before each multiplication confirm that the number of options at every stage is the same for all earlier choices; when it is not, branch first."},"mko_ids":["mko-counting-principle"]}],"title":"Concept derivation guides"}