Math question on combinations and permutations?

A music cl of 8 girls and 7 boys is having a recital. If each member is to perform once, how many ways can the program be arranged in each of the following cases? A)all girls must perform first B)a girl must perform first and a boy last C)Elisa & Doug will perform first & last, respectively D)the entire program will alternate between girls and boys E)the first, eighth, and fifteenth performers must be girls