Consider randomly selecting a student at a certain university, and let A denote the event that the selected individual has a Visa credit card and B be the analogous event for a MasterCard. Suppose that P(A) = .5, P(B) = .4, and P(A n B) = .25.
a. Compute the probability that the selected individual has at least one of the two types of cards (i.e., the probability of the event A U B).
b. What is the probability that the selected individual has neither type of card?
c. Describe, in terms of A and B, the event that the selected student has a Visa card but not a Mas- terCard, and then calculate the probability of this event.