From a group of 5 women and 7 men, how many different committees consisting of 2 women and 3 men can be formed? What if 2 of the men are feuding and refuse to serve on the committee together?

For the second question the book says that there are 5 total invalid combinations, , but then provides no explanation as to how it arrived at that conclusion.

Could someone explain how this poorly executed textbook arrived at this conclusion for me?