A sixth former is waiting for a bus to take him to town. He passes the time by counting the number of buses, up to and including the one that he wants, that come along his side of the road. If 30% of the buses travelling on that side of the road go to town, what is

(a) the most likely count he makes to the arrival of one that will take him into town,

(b) the probability that he will count, at most, four buses?