A simple arrangement of **no** elements taken **P** The **P**, where n> = 1 and p is a natural number, is any ordering of **P** elements among the **no** elements, where each way of taking the elements is differentiated by the *order* and *nature* of the elements.

That is, in **arrangements** also matters to *order* of the elements while in **combinations** only matters to *nature*, ie the elements must be different.

For example, if we want to know how many doubles we can do with 5 volleyball players, we have to use combination, because in a duo what matters is the nature (the players must be different), that is, the duo João and José is the same. double that Joseph and John, so we should not tell it.