Question

Evaluate the following expression 5P2

Answer 1

20

Explanation:

using the definition of nPr =
`(n!)/((n-r)!)`

where n! = n(n - 1)(n - 2).....× 3 × 2 × 1

5P2 =
`(5!)/(3!)` =
`(5(4)(3)(2)(1))/(3(2)(1))` = 5 × 4 = 20