Combinations
Given a set of n elements, combinations are different groups formed by the k elements of a subset such that:
The order of the elements does not matter.
The elements are not repeated.
Also, the combinations can be calculated by means of factorials:
The combinations can also be denoted as a combinatorial number: 
.
Examples
1. Calculate C(10,4).
2. A student council committee of three students has to be selected out of a class of 35 students. How many different committees can be formed?
The order of the elements does not matter.
The elements cannot be repeated.
