A local cab company maintains a fleet of 10 cabs. Each time a cab breaks down, it is repaired the same day. Assume that breakdowns of individual cabs occur completely at random at a rate of two per year.

a. What is the probability that any particular cab will run for a full year without suffering a breakdown?

b. What is the probability that the entire fleet will run for one month without a breakdown?

c. On the average, how many breakdowns would the fleet expect in a typical threemonth period?

d. What is the probability that there are more than five breakdowns between Thanksgiving Day (November 28) and New Year’s Day (January 1)?

e. For what reason might your answer in part

(d) be too low?