Number of basic events = 15?
(a) In nine basic events, only one student is a boy. The probability of the required event is p 1 = "0.6 ".
(ii) The event that at least one student is a boy includes two types of events, that is, exactly one student is a boy and both students are boys, and the probability of the requested event is P 2 =
(iii) The event that at most one student is a boy also consists of two types of events, namely, there is no boy and only one student is a boy, and the probability of the requested event is P 3 =