Question

16. There are seven books in the Harry Potter series. In how many ways can you arrange the books on your shelf?

Answer 1

There are 7 books which are arranged in 7 places.

So the total number of ways is:

`\begin{gathered} _7P_7=(7!)/((7-7)!)=7! \\ =7*6*5*4*3*2*1 \\ =5040 \end{gathered}`

Hence there are 5040 ways to arrange the books.