offers hundreds of GMAT video lessons and practice questions. Go there now.
Sign up or log in to Magoosh GMAT.

GMAT Math Equations

Here’s a brief rundown of important GMAT math equations to know.  This outline will follow the organization of the “Math Review” in the GMAT OG.

 

Arithmetic

It’s not really an equation, but you should know how to add & subtract & multiply & divide fractions.   Percents are all over the GMAT, and you should understand converting among decimals & fractions & percents, as well as the crucial topic of percent changes.  Among the big arithmetic equations are:

= the “remainder” equation (a.k.a. “rebuilding the dividend”)

= the doubling and halving method

= the laws of exponents

= the average formula (esp. for finding the sum)

= the probability “AND” and “OR” rules

= the Fundamental Counting Principle

= the formulas for permutations & combinations

= factorials

Notice, I do not list standard deviation as an equation you need to know — you need to understand the properties of standard deviation, but not the exact formula.

 

Algebra

It’s not really an equation, but you should understand the procedures for solving for x, or solving for two variables with two equations.  You should understand the rules for inequalities.  Ironically, I will not recommend perhaps the most famous high school algebra equation, the Quadratic Formula — it’s much more important on the GMAT to know how to solve quadratics by factoring.  Algebra equations important on the GMAT include:

= the FOIL pattern

= absolute values and negatives produce befuddling equations

= function notation

 

Geometry

The beautiful realm of geometry entails several important formulas, starting with the great granddaddy of them all:

= The Pythagorean Theorem

others include:

= area of a triangle (A = 0.5bh)

= area of a rectangle (A = bh)

= c = 2*pi*r

= Archimedes’ formula: A = pi*r^2

= Volume of a box = (height)*(width)*(depth)

= slope in the x-y plane

= slopes for parallel & perpendicular lines

= the special properties of the line y = x

Oddly, I am going to strongly recommend NOT to memorize a formula for finding distance in the x-y plane — I explain what to do instead at that link.  :)

 

Word Problems

= rate, distance, and time

= work rate

= mixture equations

= (profit) = (revenue) – (cost)

Problems of interest and discount just involve the same percent equations discussed above.

 

See also:

How to study for GMAT math

Mathematical thinking on the GMAT

 

If you have questions or feedback about the GMAT math equations you’ll need to know, please let us know in the comments section below.

 

About the Author

Mike McGarry is a Content Developer for Magoosh with over 20 years of teaching experience and a BS in Physics and an MA in Religion, both from Harvard. He enjoys hitting foosballs into orbit, and despite having no obvious cranial deficiency, he insists on rooting for the NY Mets. Follow him on Google+!

No comments yet.


Magoosh blog comment policy: To create the best experience for our readers, we will approve and respond to comments that are relevant to the article, general enough to be helpful to other students, concise, and well-written! :) If your comment was not approved, it likely did not adhere to these guidelines. If you are a Premium Magoosh student and would like more personalized service, you can use the Help tab on the Magoosh dashboard. Thanks!

Leave a Reply