How many three-element subsets of {1,2,3,4} are there that do not contain the pair of elements 2 and 4?
Choose the correct choice from the following choices
A) 1  B) 2  C) 3  D) 4  E) 5
Required subsets are = {1,2,3}, {1,3,4}= 2   Answer: 2
<result>B</result>
How many three-element subsets of {1,2,3,4} are there that do not contain the pair of elements 2 and 4?