This is a standard permutation problem. It's a permutation problem as opposed to a combination because each book is considered distinct. About as basic a permutation problem as as you can get.

A truly basic permutation problem would have been. How many ways can you arrange 5 books. Answer would have been 5 ! or 5x4x3x2x1=120

For this problem we use the permutation formula with a slant of moving the books around N number at a time.

The formula for permutation is

Total Units ! /(Total-N) !

N is the amount of books taken at a time.

Plugging in, we get

5 books !/ (5-3) !

Solving we get

5x4x3x2x1/(2x1)

5x4x3x2/2=60

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Davefor MBA