## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$P(8,3) = 336$
Use the formula $P(n, r)=\dfrac{n!}{(n-r)!}$: $P(8,3) \\ = \dfrac{8!}{(8-3)!} \\= \dfrac{8!}{5!} \\= \dfrac{8\times7\times6\times5!}{5!} \\= 8\times7\times6 \\ = 336$