Calculate the number of combinations - Java Quiz Question

Write a program to calculate the total number of combinations possible.

Input (Integer, Integer) Output (Integer)
17C3 680
4C2 6
15C4 1365
10C1 1
21C21 1
0C5 null



class NumberOfCombinations
{
    public static void main(String s[])
    {
        System.out.println("Total number of combinations of 17C3 : " + numberOfCombinations(17, 3));

    }


    public static Integer numberOfCombinations(int total, int choicesCount) {
    }

}