Word Problem Help

Question

1. 1.Question:Amy is shelving books in a display in the school library. She has4 comic books, 7 horror, & 6 detective and mystery.

how many ways can she arrange the books on the shelf for shelf? explain ( why do you have to use factorials for this problem?)

Answer 1

Factorials are not necessary. They are notations that minimize the number of symbols.

For the comic books: (4)(3)(2)(1) = 24 combinations, or 4!

For the horror books: (7)(6)(5)(4)(3)(2)(1) = 5040, or 7!

For the mystery books: (6)(5)(4)(3)(2)(1) = 720, or 6!