Question

How do you evaluate 20P2?

Answer 1

Steps and result are outlined below...

Explanation:

The general formula for a permutation is

`""_nP_r = (n!)/(n-r!)`

In this case, `n=20` and `r=2`, so our equation becomes

`""_20P_2 = (20!)/(18!) = (20xx19) = 380`