From a group of 5 freshmen, 3 sophomores, 4 juniors, and 6 seniors, how many 5-person committees are possible if the chair is a junior and there must be exactly 2 seniors?

The number of five-person committee possible is 3. There are 6 seniors and each group requires exactly 2 seniors. 6 divided by 2 is equals to 3. Therefore, each of the 3 committee has 1 junior as chair, 2 required number of seniors and the rest would be either the remaining 1 junior or the freshmen and sophomores.