In: Statistics and Probability
In how many ways can you arrange 5 books in a bookshelf? Give details
For the first place in your bookshelf, you can choose any of the 5 books. For the second place you have a choice of 4, etc.
The total number of possibilities are thus: 5⋅4⋅3⋅2⋅1
which in maths is abbreviated to
5!
(pronounced as 5 factorial).
n! or "n-factorial" means: multiply all numbers from 1 up to and including n
Most calculators have an x! button. In GC's it's in one of the menus.
120 way