Jul 24, 2008

SAT Prep | Sets

A set is a group of items. Each item in a set is called an element of that set. For example, let set X represent the set of positive odd integers between 0 and 10. This set has five elements: the numbers 1, 3, 5, 7, and 9. The elements of a set are often written within brackets, as shown next.

X = {1, 3, 5, 7, 9}

The union of two sets includes all of the elements in the first set and all of the elements in the second set. If set Y = {6, 7, 8, 9}, then the union of sets X and Y is the set {1, 3, 5, 6, 7, 8, 9}.

The...