Mark (√) against the correct answer in each of the following:

A couple has 2 children. What is the probability that both are boys. If it is known that one of them is a boy?

_{The couple has two children and one is known to be boy,}

_{The probability that the other is boy will be =}

_{Total outcomes are 3,}

_{The first child is a boy, the second girl}

_{The first child is a girl, the second boy}

_{The first child is a boy, second boy}

_{The favourable outcome is one,}

_{Thus, the probability that the other is boy will be}

_{⇒ 1/3}