The main difference between permutation and combination is that in permutations, the order of items matters, while in combinations, the order does not matter. Let us look at the table below to better understand the key differences:
Permutation |
Combination |
Used when the order of items is important. |
Used when the order of items does not matter. |
Applicable for items of different types. |
Applicable for items of the same type. |
The value of permutation is always higher because it counts different arrangements of selected items. |
The value of combination is lower since it only counts selections, not arrangements. |
Multiple permutations can be derived from a single combination. |
Only one combination can be formed from a single permutation. |
Formula: nPr = n! / (n−r)! |
Formula: nCr = n! / r! * (n−r)! |
Example: For three items A, B, C, the permutation of two items is: AB, BA, BC, CB, CA, AC. |
Example: For three items A, B, C, the combination of two items is: AB, BC, CA. |