A Permutation

Calculate the permutation: 5P2

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:
$$$P_{(5,2)}=\frac{5!}{(5-2)!}=\frac{5!}{3!}=\frac{5\cdot 4\cdot 3!}{3!}=20$$$
20