Question

I need help please help me

Answer 1

12P3
= 12 x 11 x 10 x 9! / 9! 
= 12 x 11 x 10  
= 1320

Answer 2

$_{n}P_{k}=\frac{n!}{(n-k)!}$
$_{12}P_{3}=\frac{12!}{(12-3)!}=\frac{12!}{9!}=\frac{12\times11\times10\times9\times8\times7\times6\times5\times4\times3\times2\times1}{9\times8\times7\times6\times5\times4\times3\times2\times1}=\frac{479,001,600}{362,880}=1,320$

OR 

$_{12}P_{3}=\frac{12!}{(12-3)!}=\frac{12}{9!}=\frac{12\times11\times10\times9\times8\times7\times6\times5\times4\times3\times2\times1}{9\times8\times7\times6\times5\times4\times3\times2\times1} = 12\times11\times10 = 1,320$