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MHT CET · Maths · Probability

A parents has two children. If one of them is boy, then the probability that other is, also a boy, is

  1. A \(1 / 2\)
  2. B \(1 / 4\)
  3. C \(1 / 3\)
  4. D None of these
Verified Solution

Answer & Solution

Correct Answer

(C) \(1 / 3\)

Step-by-step Solution

Detailed explanation

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 \(P(B / A)=\frac{P(A \cap B)}{P(A)}=\frac{1 / 4}{3 / 4}=\frac{1}{3}\)