The probabilities of two students A and B coming to the school in time are and 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.

As A and B are independent events, so A’ and B’ are also independent.

We know that if A and B are independent events then

P(A ∩ B) = P(A)P(B)

As we have to find the probability of the event such that only one of them come to the school on time.

∴ P(required event) = P(A’ ∩ B) + P(A ∩ B’)

As A and B are independent events

⇒ ∴ P(required event) = P(A’)P(B) + P(A)P(B’)

As, P(A) = 3/7 ⇒ P(A’) = 1 - 3/7 = 4/7

And P(B) = 5/7 ⇒ P(B’) = 1 – 5/7 = 2/7

⇒ ∴ P(required event) =

Thus,

P(required event) = 26/49

Benefit of coming school on time – by doing this we learn the value of time and importance of discipline