정답
$C(n, r) = \frac{n!}{r!(n - r)!}$ (order does not matter); $P(n, r) = \frac{n!}{(n - r)!}$ (order matters).
해설
A committee of 3 from 10 is a combination $C(10, 3) = 120$. Electing President, VP, and Secretary is a permutation $P(10, 3) = 720$.
홈 / 라이브러리 / ACT Mastery: English, Math, Reading & Science / AI 플래시카드
How do you calculate combinations $C(n, r)$ and permutations $P(n, r)$?
덱 'ACT Mastery: English, Math, Reading & Science'의 플래시카드.