UPSC NDA Math Model Paper 5

A committee of 3 is to be formed from a group of 2 boys and 2 girls.
Here are two boys B1 and B2 and two girls G1 and G2.
Sample space =S={B1B2G1,B1B2G2,G1G2B1,G1G2B2}
⇒n(S)=4
A: The event that the committee consists of 2 boys and 1 girl
A={B1B2G1,B1B2G2}
⇒n(A)=2
probability that the committee consists of 2 boys and 1 girl =P(A)=

n(A)

n(S)

=

2

4

Hence, A committee of 3 is to be formed from a group of 2 boys and 2 girls, the probability that the committee consists of 2 boys and 1 girl

1

2