Stage 32 · Counting, Permutations, Combinations & the Binomial Theorem

32.2.6 Permutation Problems Combined

32.2 Permutations: When Order Counts Too

Point 6 of 6

32.2.6 Permutation Problems Combined

Core idea

Forming numbers from digits, arrangements with a fixed order, and the like: translate each restriction into 'which step comes first', then apply the permutation formula

Module goal. Understand counting where the selection is ordered, master the permutation formula and factorials, and learn to spot permutation problems that carry restrictions
eastmath.com · 32.2 Permutations: When Order Counts Too · 32.2.6 Permutation Problems Combined