For each family: X p(X) BB 1/4 BG 1/4 GB 1/4 GG 1/4 1/4 of the time the first family will have two girls, and 1/4 of those times the second family will also have two girls. Then 1/4 of those times the third family will also have two girls. Then 1/4 of those times the fourth family will also have two girls. Then 1/4 of those times the fifth family will also have two girls. That's (1/4)(1/4)(1/4)(1/4)(1/4) = (1/4)5 = 1/45 = 1/1024. Edwin