An office has two clerks and three people, A,B, and C, enter simultaneously. A and B begin service at the two clerks, which C waits for the first available clerk. Assume that the service time T has an exponential pdf (i.e. T ~ exp(-lamda)).

a) What is the probability that A is the last to finish the service?

b) Compute the expected amount of time before C is done (i.e., C's combined waiting and service time).