(4) let s - {a, b,c, d,c}. (a) list all of the 2-permutations of sin an organized manner. how many are there? (b) list all of the 2-combinations of sin an organized manner. how many are there? (c) list all of the 3-combinations of s in an organized manner. how many are there?
(d) on the previous page, you should have gotten the same number of 2 combinations of s as 3-combinations. explain why we should expect these numbers to be the same.