How many two-element subsets of <1, 2,3,4,5> are there that do not contain the pair of elements 2 and 4?  Choose the correct option.
A) 1  B) 2  C) 4  D) 5  E) 9
5C2 - 1 = 9 Answer is 9
<result>E</result>
How many two-element subsets of <1, 2,3,4,5> are there that do not contain the pair of elements 2 and 4?