| Permutations |
 |
|
A permutation of n taken m at a time is defined as an ordered selection of m out of the n items. The total number of all the possible permutations is denoted as:  |
| Combinations |
|
|
A combination of n taken m at a time is defined as a selection of m out of the n items without regard to the order. The total number of all the possible combinations is denoted as:  |
