Question

How many ways can a librarian arrange 15 books on a top shelf if she has 20 books from which to pick?

20!/5!
20!/15!
15!/5!

Answer 1

The correct answer is A turned this in got a 100 hoped this helped ya.

Answer 2

Use the permutation formula
nPr = (n!)/((n-r)!)
20P15 = (20!)/((20-15)!)
20P15 = (20!)/(5!)

The final answer is choice A