A father has 3 children with at least one boy. The probability that he has 2 boys and 1 girl is `1//4` b. `1//3` c. `2//3` d. none of these

Options

A. `1//4`
B. `1//3`
C. `2//3`
D. None of these

Answer

B

Explanation

Consider the following events:
A: Father has at least one boy
B: Father has 2 boys and one girl
Then,
A= one boy and 2 girls, 2 boys and one girl, 3 boys and no girl `AnnB=2` boys and one girl
Now, the required probability is
`=P(A//B)=(P(AnnB))/(P(A))=1/3`