Question

How do you evaluate ${}^{8}P_3$?

Answer 1

Find the value of the given term?

${}^{n}P_r=\frac{n!}{\left(n-r\right)!}$

Values of $n$and $r$

$$\begin{gathered} n=8 \\ r=3 \end{gathered}$$

Substitute $n$ and $r$ values in the above formula

$$\begin{gathered} {}^{8}P_3=\frac{8!}{\left(8-3\right)!} \\ =\frac{8!}{5!} \\ =\frac{8\times 7\times 6\times 5!}{5!} \\ =336 \end{gathered}$$

Hence the answer is $336$