A couple plans to have three children. What is the probability that (a) they have all boys?

A couple plans to have three children.

What is the probability that

(a) they have all boys?
(b) they have at least one girl?

Solution for Question (a)

There are `"2"^3` = 8 possible combinations for two genders for three children.

Solution for Question (b)

There are (GGG, GGB, BGG, GBG) = 4 combinations where at least two of the children are girls.

Thus, there is a `4/8` = `1/2` probability that there will be at least two girls in the family of three children.