Molly owns 5 different mathematics books and 3 different computer science books.
(a) If Molly wishes to fill 6 positions on a shelf where the first 4 positions are to be occupied by math books and the last 2 by computer science books, in how many ways can this be done? (
b) In how many ways can Molly put all of the books on the shelf?
(c) If Molly wants to put all of the books on the shelf with all the math books together and all the computer science books together, in how many ways can this be done?