What Is the Difference Between Permutation and Combination? The permutation is the number of different arrangement which can be made by picking r number of things from the available n things. The combination is the number of different groups of r objects each, which can be formed from the available n objects.

Why is permutation different from combination?

The difference between combinations and permutations is ordering. With permutations we care about the order of the elements, whereas with combinations we don't. For example, say your locker “combo” is 5432. If you enter 4325 into your locker it won't open because it is a different ordering (aka permutation).

How can you tell permutation and combination easily?

Combinations are much easier to get along with – details don't matter so much. To a combination, red/yellow/green looks the same as green/yellow/red. Permutations are for lists (where order matters) and combinations are for groups (where order doesn't matter). In other words: A permutation is an ordered combination.