Of the 10,000 students at a certain university, 7000 have Visa cards, 6000 have MasterCards, and 5000 have both. Suppose that a student is randomly selected.
a. What is the probability that the selected student has a Visa card?
b. What is the probability that the selected student has both cards?
c. Suppose that you learn that the selected individual has a Visa card (was one of the 7000 with such a card). Now what is the probability that this student has both cards?
d. Are the outcomes has a Visa card and has a Master- Card independent? Explain.
e. Answer the question posed in Part (d) if only 4200 of the students have both cards.