Question

Given 7 distinct objects, the number of ways to arrange 4

objects at a time is
Select one:
a.
840
b.
28
c.
5040.
d.
35

Answer 1

840 different ways

Explanation:

P(n, r) = n! / (n - r)!

P(7, 4) = 7! / (7 - 4)!

= 7! / 3!

= (7 * 6 * 5 * 4) / (3 * 2 * 1)

= 840