Afisherman catches fish according to a poisson process with rate lambda = 0.6 per hour. the fisherman will keep fishing for two hours. at the end of the second hour, if he has caught at least one fish, he quits; otherwise, he continues until he catches one fish. (a) find the probability that he stays for more than two hours. (b) find the probability that the total time he spends fishing is between two and five hours. (c) find the expected number offish that he catches. (d) find the expected total fishing time, given that he has been fishing for four hours.