Question

A couple has two children . Find the probability that both the children are (i) males , if it is known that at least one of the children is male . (ii) females, if it is known that the elder child is a female .

Answer 1

$i)$If it is known that at least one of the children is male.

Then possible outcomes are:

i)Both Males ii)One male and one female.

Then probability that both the childrens are male is;$\frac{1}{2}$

$ii)$ If it is known that the elder child is a female.

Then possible outcomes are:

i)Both female ii)One male and one female.

Then probability that both the childrens are female is:$\frac{1}{2}$