Alex chooses a number at random from the set {1, 2, 3, 4, 5}. Winnie also chooses a number at random from the same set. (They can choose the same number.) What is the probability that the product of their numbers is at least 4?
There are 25 possible choices ( w = with)
1 w 1 2 3 4 5
2 w 1 2 3 4 5
3 w 1 2 3 4 5
4 w 1 2 3 4 5
5 w 1 2 3 4 5 the bold choices produce a product 4 or greater 20 out of 25 choices is 20/25 = 4/5 = .80 = 80 %
( pick your format)