Statistics Problem

Question

Two friends are shooting at a target. John, the first of the 2 friends, has a 60% chance of hitting it. Alex, the second, has a 80% probability to hit it. Assume that these probabilities are independent.

What is the prob that neither one will hit the target?

What is the prob that exactly one of them will hit the target?

Answer 1

.4x.2 = .08 = 8% chance neither hits the target

(1-.6)(1-.8) = .4(.2) = .08 = 8%

.6(.2) + .4(.8) = .12+.32 = .44 = 44% chance exactly one will hit the target

Pr(both hit the target) = .6(.8)= .48= 48% chance

8% + 44% + 48% = 100%