Permutation

Calculate the permutation: 4P2

Hint
The number of different permutations of "n" distinct objects taken "r" at a time is:
$$$P_{(n,r)}=\frac{n!}{(n-r)!}$$$
Hint 2
Permutation format: $$nPr$$
The number of different permutations of "n" distinct objects taken "r" at a time is:
$$$P_{(n,r)}=\frac{n!}{(n-r)!}$$$
Solving the permutation:
$$$P_{(4,2)}=\frac{4!}{(4-2)!}=\frac{4!}{2!}=\frac{4\cdot 3\cdot 2!}{2!}=12$$$
12