Answer
$_8P_3=336$
Work Step by Step
RECALL:
$_nP_r = \dfrac{n!}{(n-r)!}$
Use this definition to have:
$\require{cancel}
_8P_3=\dfrac{8!}{(8-3)!}
\\_8P_3=\dfrac{8!}{5!}
\\_8P_3 = \dfrac{8(7)(6)(5!)}{5!}
\\_8P_3 = \dfrac{8(7)(6)\cancel{(5!)}}{\cancel{5!}}
\\_8P_3=336$
