Question

Find the probability that when a couple has twotwo ​children, at least one of them is a boyboy. ​(Assume that boys and girls are equally​ likely.) The probability is . 5.5 that at least one of the twotwo children is a boyboy.

Answer 1

0.75

Explanation:

It is given that having a boy or girl as children are the two events which are equally likely.

i.e. Probability of having a boy or a girl is equal to
`(1)/(2)` or 0.5.

Let P(B) be the probability of having a boy and P(G) be the probability of having a girl child.

So, P(B) = P(G) = 0.5

To find: Probability that out of two children, atleast one boy is born.

Required probability = 1 - Probability that both the children are girls

Required probability :

`\Rightarrow 1-(0.5 * 0.5)\\\Rightarrow 1 - 0.25\\\Rightarrow 0.75`

So, the probabilty that atleast one boy is born out of two children is 0.75.