Question

The probabilities of two students A and B coming to the school in time are 3/7 and 5/7 respectively. Assuming that the events, ‘A coming in time’ and ‘B coming in time’ are independent, find the probability of only one of them coming to the school in time. Write at least one advantage of coming to school in time.

Answer 1

Let E1 and E2 be two events such that

E1 = A coming to the school in time.

E2 = B coming to the school in time.

Here P (E1) = 3/7 and P (E2) = 5/7

⇒ P(bar E1) = 4/7, P(bar E2) = 2/7

P (only one of them coming to the school in time) = P(E1)P(bar E2) + P(bar E1)P(E2)

= 3/7 x 2/7 + 5/7 x 4/7 = (6 + 20)/49 = 26/49

Coming to school in time i.e., punctuality is a part of discipline which is very essential for development of an individual.