The combination is a mathematical operation that shows how many different ways to choose when choosing from a set. When making the combination calculation, there is no obligation to pay attention to the order of the group elements.
The order of subset elements is not taken into account in the combination. For example, for a cluster with H, E, S, A, P elements, the EH subset is not counted because the HE subset and the EH subset consist of the same elements. According to the combination, it is the same in two subsets.
Combination calculation formula, C (n, r) = n! / (r! (n-r)!).
When we create the 2-element subsets of the H, E, S set, it will be HE, HS and ES. If we calculate this with the combination formula, C (3, 2) = 3! / (2! X (3 - 2)!), The result from this calculation will be 3.
The difference between permutation and combination is the difference of sort logic. For example, HE cluster and EH cluster are separate clusters in permutation logic. But in combination, these two sets are counted as the same set.
If you want to calculate permutations please click here , and click here to see other calculations related to statistics.