Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A parents has two children. If one of them is boy, then the probability that other is, also a boy, is
MathematicsProbabilityMHT CETMHT CET 2008
Options:
  • A $1 / 2$
  • B $1 / 4$
  • C $1 / 3$
  • D None of these
Solution:
1647 Upvotes Verified Answer
The correct answer is: $1 / 3$
Total cases are $B B, B G, G B, G G=4$ Favourable cases are $B B, B G, G B=3$ Let $P(A)=$ Probability of a boy in two children
$$
=\frac{3}{4}
$$
The probability that the second child is also a boy is $P(A \cap B)=\frac{1}{4}$
We have to find $P(B / A)=\frac{P(A \cap B)}{P(A)}=\frac{1 / 4}{3 / 4}=\frac{1}{3}$

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.