Three Claims About $x$ and $y$

Difficulty: Medium · Topics: Discrete Mathematics, Sets, Subsets

A=\1,2,3,4,5,x,y\

Which of the following statements about this set are true?

I. 15 of the four-element subsets contain x and y.

II. 96 of the subsets contain x or y.

III. 48 of the subsets contain exactly one of x and y.