#### Answer

$7,920$

#### Work Step by Step

RECALL:
$P(n, r) = \dfrac{n!}{(n-r)!}$
Use the formula above to obtain:
$P(11, 4) = \dfrac{11!}{(11-4)!}
\\P(11, 4) = \dfrac{11!}{7!}
\\P(11, 4) = \dfrac{11(10)(9)(8)(7!)}{7!}$
Cancel the common factor $7!$ to obtain:
$P(11, 4) = 11(10)(9)(8)
\\P(11, 4) = 7,920$