What is the value of 7p5?

a.5040
b.2520
c.42
d.21

The answer is B.2520

For permutation P we will use:
nPr = n!/(n-r)!
7P5 = ?
n = 7
r = 5
7P5 = 7!/(7-5)!
       = (7 * 6 * 5 * 4 * 3 * 2 * 1)/2!
       = 5040/(1 * 2)
       = 5040/2
       = 2520

Just turn the whole gym into pie