Question

Assume the probability is 1/2 that a child born is a girl. What is the probability that if a family is going to have four children, they will have 3 boys and 1 girl (in any order)?

Answer 1

The probability that a child born is a girl is 1/2, thus the probability of a child born is a boy is 1-1/2= 1/2.

Then, to find the probability that if a family is going to have four children, they will have 3 boys and 1 girl (in any order) can be found as follows:

`\begin{gathered} \text{BBBG} \\ \text{BBGB} \\ \text{BGBB} \\ \text{GBBB} \\ \text{There are 4 possibilities of getting 3 boys and 1 girl} \\ \text{The total number of possibilities is} \\ 2^4=16 \\ \text{Thus, the probability is} \\ P=(4)/(16)=(1)/(4) \end{gathered}`

The probability is 1/4