1.74. A student is known to arrive late for a class 40% of the time. If the class meets five times each week find: (a) the probability the student is late for at least three classes in a given week, and (6) the probability the student will not ber late at all during a given weck. 1.7-5. An airline in a small city has five departures each day. It is known that any given flight has a probability of 0.3 of departing late. For any given day find the probabilities that: (a) no flights depart late, (b) all flights depart late, and (c) three or more depart on time.