Ihave three questions:
1. 4 students from a class of 15 are going to be chosen to be on the dance committee. find the number of different 4-person committees that can be made.
2. leslie has 7 books. there is enough space on a shelf for 3 books. in how many ways can 3 of the 7 books be arranged on the shelf? (for this one i keep getting the answer 35, but its coming up wrong on my assignment.)
3. out of the 12 girls who tried out for the softball team, 10 will be chosen for the team. find the number of different 10-person teams.