Question

What is the value of 9P5 ?

Answer 1

$\bf _nP_r=\cfrac{n!}{(n-r)!}\qquad \qquad \qquad _9P_5=\cfrac{9!}{(9-5)!}$

check your calculator for the [!] factorial button.

also bear in mind that most calculators also have an [ₙPᵣ] button, to get Permuations, and you can just use that.