Question

A professor has 7 books they are trying to arrange on a shelf. If the professor selects 3 books at a time, how many different arrangements of books can they come up with?
i got 210 but im not sure

Answer 1

The number of different arrangements of books is 210

What is the formula for Permutation?

Permutation in mathematics can be calculated by using the formula

nPr = $\frac{n!}{(n - r)!}$

where

• nPr = Permutation required

• n = total number of objects = 7

• r = number of objects selected = 3

nPr = $\frac{7!}{(7-3)!}$

nPr = $\frac{5040}{24}$

nPr = 210

Therefore, the required number of ways is 210

learn more about permutations here brainly.com/question/112112