Question

Mohan is father of 3 children with atleast one boy. The probability that he has 2 boys and 1 girl is
1. 1/2
2. 1/3
3. 1/4
4. 2/3

Answer 1

Correct Answer - Option 2 : 1/3

Formula used:

Let the event be E, then

P(E) =  Number of favorable outcomes/Number of total Possible outcomes

Calculation:​

Father has three children with atleast one Boy

Atleast one out of 3 means the number of Boys should atleast be one and it can be up to 3.

Let's represent boy with B and girl with G

Then possible outcomes are BBB, BBG, BGG

And, the favorable outcome i.e. 2 boys and 1 girl is BBG 

P(E) =  Number of favorable outcomes/Number of total Possible outcomes

⇒ P(E) = 1/3

∴ The probability that he has 2 boys and 1 girl is 1/3