Given a set S a, b, c, find the subsets of two elements (r - 2) when 1. repetition is allowed and order matters. 2. repetition is not allowed but order matters. 3. repetition is not allowed and order does not matter. 4. repetition is allowed but order does not matter. 5. Show all the permutations (order matters) of the three elements in set S. Identify the number of subsets for each condition in the previous problem and link cach condition with one of the followings: n', ncr, np,, n!, and (n+r-1