Question

find the probability that a family with four children has exactly four girls. Assume that the probability a girl is born is the same as the probability a boy is born.

Answer 1

This is like the number of ways to get 4 heads when flipping a coin.

There is only one way to have exactly 4 girls in a family of 4. And there are 2^4 combinations of boys and girls in a family of 4;

So probability of exactly 4 girls is 1/2^4.