Answer
$24$
Work Step by Step
Using $n!=n(n-1)(n-2)\cdot\cdot\cdot(3)(2)(1)$ or the factorial of a number, the given expression, $
4!
,$ is equal to
\begin{array}{l}\require{cancel}
4(3)(2)(1)
\\\\=
12(2)(1)
\\\\=
24(1)
\\\\=
24
.\end{array}