Question

Marcus is choosing 4 books to read from a list of 15 books. If order matters, how many ways can he choose to read the books?

4

32,760

23,760

60

Answer 1

32,760

Explanation:

Given :

Since the order matters, we use the permutation relation :

Recall :

nPr = n! ÷ (n - r)!

n = 15 ; r = 4

15P4 = 15! ÷ (15 - 4)!

15P4 = 15! ÷ 11!

15P4 = (15 * 14 * 13 * 12)

15P4 = 32,760