A particular committee needs one 7-grader and three 8-graders. If there are four 7-graders and six 8-graders applying to the committee, in how many ways can the committee be filled?
This is a combinations problem
There are 4 seventh graders and we want to choose one of them......
The number of ways this can be done = C (4,1) = 4 (1)
There are six eighth graders and we want to choose any three of them
The number of ways this can be done = C(8,3) = 56 (2)
So....the total possible committees = (1) * (2) = (4) * (56) = 224
Thank you soo much CPhil, but unfortunately that isn't the correct answer. I am taking a Probability and Counting class on AOPS like Mellie was....