## CLEP Guides

American Government Biology College Mathematics General CLEP General Tips Human Growth And Development Humanities Introductory Psychology Principles Of Marketing Sociology US History 1 US History 2# What are Sets?

Usually when you write out sets they are shown as following. Taking our example of all the odd number between 1 and 10 we would write this as: S={1,3,5,7,9} where S just stands for set, and the brackets contain the set itself. Also note that S can be anything so in the previous example it could have been E={1,3,5,7,9}. The numbers within the brackets are called elements. So in this example 1,3,5,7,9 are elements of S.

There is also a special way to write The symbol for elements is**∈ ∉ **so you could say 3

**∈**S. If a number is not in the set you put a line through the is in symble, such as 2

**?**S .

## Sample Problems

Write Out the set for : A={Even Whole Numbers Between 1 and 11}

Is 6 **∈**A?

Is 8 ** ∉ **A?

If **∈** is a box your probably using internet explorer. It doesn't render this symbol right. Basically it looks like an "E". This page is best viewed in Firefox download it here.