A couple plans to have three children. There are eight possible arrangements of girls and boys. For example, GGB means the rst two children are girls, and the third child is a boy. All eight arrangements are (approximately) equally likely. a) (5 pts) Write down all eight arrangements of the sexes of three children. What is the probability of any one of these arrangements? b) (5 pts) Let X be the number of girls the couple has. What is the probability that X = 2? c) (5 pts) Starting from your work in part (a), nd the distribution of X. That is, what values can X take, and what are the probabilities for each value