


Math 101
Don’t say we didn’t warn you. We told you in the previous chapter that
we’d cover every math concept included on the GRE, and this chapter makes good
on that promise. Yeah, Math 101 is long, very long, but you don’t necessarily
need to read it straight through—it’s here as a resource to
help you study any and all topics you need to review. If you’re good with
triangles, by all means skip ‘em. If exponents have always baffled you, key in
on that section. If you’ve never even heard of modes or frequency
distributions—well, you’ll know what to do when you get to that part. If you’re
a total super math genius, pass Go, collect $200, and proceed right to chapter
3. (That’s just a Monopoly expression. No one’s really going to
give you $200.) Use as much or as little of what follows as you need, but make
sure you have a good grasp of the concepts covered in this chapter if you want
to ace GRE Math.
You’ll see that we have highlighted all the math formulas, which are
integral to solving any GRE Math question in this chapter. Additionally, in the
subsequent chapters, we have bolded all the math concepts that turn up in our
explanations to the practice questions. That way, if anything seems difficult or
particularly confusing, you can easily reference that particular math concept
and come back here to get some targeted study.
As we discussed in chapter 1, GRE Math questions take many forms, but they
all test one or more of four main subject areas:
 Arithmetic
 Algebra
 Geometry
 Data Analysis
We begin with one of the socalled three R’s of education, which for some
reason doesn’t even begin with the letter “R”. . .
