(This problem is for students who are working on the relationship between k-element permutations and k-element subsets.) Write down all three element permutations of the five element set {1, 2, 3, 4, 5} in lexicographic order. Underline those that correspond to the set {1, 3, 5}. Draw a rectangle around those that correspond to the set {2, 4, 5}. How many three-element permutations of {1, 2, 3, 4, 5} correspond to a given 3-element set? How many three-element subsets does the set {1, 2, 3, 4, 5} have?