How many two-element subsets of <1, 2,3,4,5,6,7,8,9> are there that do not contain the pair of elements 2 and 4?	Answers: A) 21 B) 22 C) 24 D) 35 E) 36
9C2 - 1 = 35 Answer is 35
<result>D</result>
How many two-element subsets of <1, 2,3,4,5,6,7,8,9> are there that do not contain the pair of elements 2 and 4?