Question

Hello, can you please help me with question number 1? use the formula for nPr to evaluate each expression:9P4

Answer 1

SOLUTION:

Case: Permutation

nPr=

$^nP_r=\frac{n!}{(n-r)!}$

Method:

$\begin{gathered} ^9P_4=\frac{9!}{(9-4)!} \\ =\frac{9!}{5!} \\ =9\times8\times7\times6\times\frac{5!}{5!} \\ =9\times8\times7\times6 \\ =3024 \end{gathered}$

Final answer:

9P4= 3024