How may combinations of three can you get from five?
60 if you allow permutations, 20 if not. 60 is found by suing
the permutation function 5P3, and we get 20 simply by dividing by 3
as there will be 3 permutations from a group of 3 numbers while
keeping the order the same e.g. (1,2,3) , (2,3,1) and (3,1,2).