4) There are two traffic lights on the route used by Pikup Andropov to go from home to school. Suppose

P(stops at first light) = .4, P(stops at second light) = .3, and P(stops at both lights) = .15. Find the

following probabilities:

A) P(must stop for at least one light)

B) P(doesn't stop at either light)

C) P(must stop at exactly one light)

D) P(must stop at only the first light)