Question: A committee of size k is chosen from a group of n women and m men. All possible committees of size k are equally likely. Let X and Y be the numbers of women and men on the committee, respectively.
(a) Find the joint PMF of X and Y. Be sure to specify the support.
(b) Find the marginal PMF of X in two different ways: by doing a computation using the joint PMF, and using a story.
(c) Find the conditional PMF of Y given that X = x.