The manager of a youth-oriented clothing store at the local mall has determined that 27% of the males who enter the store make a purchase, while 64% of the females who enter the store make a purchase. A male and a female customer are independently and randomly selected.

a. What is the probability both customers make a purchase?

b. What is the probability exactly one customer makes a purchase?

c. What is the probability that at least one customer makes a purchase?