I have 5 different mathematics textbooks and 4 different psychology textbooks. In how many ways can I place the 9 textbooks on a bookshelf, in a row, if there must be a psychology textbook in the middle?

Guest Jan 19, 2021

#1**0 **

There are 4 possibilities for the middle book

Since the books are all different, we can simply use 8! for the rest

8!*4 is your answer

MooMooooMooM Jan 19, 2021