Question

Assume that each born child is equally likely to be a boy or a girl. If a family has two children, what is the conditional probability that both are girls given that 

i. the youngest is a girl? 

ii. atleast one is a girl?

Answer 1

A family has 2 children,

then sample space = S = {BB, BG, GB, GG} where B stands for boy and G for girl.

i. Let A and B be two event such that

ii. Let C be event such that

C = at least one is a girl = {BG, GB, GG}