Reconsider Exercise 11.1.8 about three business executives dropping their cell phones in an elevator and then picking them up at random. 

a. Report the probability that exactly one person picks up the correct phone. 

b. Report the probability that exactly two people pick up the correct phone. 

c. Report the probability that all three people pick up the correct phone. 

d. Report the probability that at least one person picks up the correct phone.

Data from Exercise 11.1.8

Suppose that three business executives (call them Abby, Bernice, and Caitlin) drop their cell phones in an elevator and then pick them up at random.