## Geometry: Common Core (15th Edition)

$_{8}$P$_{5}$ is a permutation. To solve, use the permutation formula: $_{n}$P$_{r}$ = $\frac{n!}{(n-r)!}$ Plug in 8 for "n" and 5 for "r": $_{n}$P$_{r}$ = $\frac{n!}{(n-r)!}$ $_{8}$P$_{5}$ = $\frac{8!}{(8-5)!}$ = $\frac{8 \times7\times6\times5\times4\times3\times2\times1}{3\times2\times1}$ = $\frac{40,320}{6}$ = 6,720