A college student is randomly selected. Let A be the event that the selected individual has a Visa credit card and B be the event that he has a MasterCard. It is known that P ( A ) =0.45 , P ( B ) =0.43 , and P ( A ∩ B ) =0.21 . Compute the following probabilities (a Venn diagram might help). (Round your answers to four decimal places.)a) What is the probability that he has at least one card?

b) P (B | A)

c) P (B^c | A)

d) Given that the selected individual has at least one card, what is the probability that it is a Visa Card?