**Update 6/8/12: Even better than a cheat sheet– download our free GRE Math Formula eBook!**

Before walking into the GRE, it is a good idea to know the following formulas/tidbits. In fact, not knowing the information below can seriously hurt your chances of answering a question correctly.

At the same time, while this is a very useful cheat sheet, do not just memorize formulas without actually applying them to a question. Often students will see a question and will assume that a certain formula is relevant. This is not always the case. So make sure you practice using the formulas so you will know when they pertain to a question.

Not sure when to use these math formulas? Magoosh GRE prep offers lesson videos and practice questions to help you learn to put these formulas to use. And our Android/iPhone Prep App allows you to access that content on the go.

And now…GRE math formulas!

## Interest

Simple Interest: , where P is principal, r is rate, and t is time

Compound Interest: , where n is the number of times compounded per year

## Work Rates

, where T is the time to completion of a task when two workers are combining effort.

## Sets

## Distance, Rate, and Time

,

## Circles

## Squares

, where s = side

## Rectangles

, where l = length and w = width

## Trapezoids

## Polygons

, where n = # of sides

## The Distance Formula

## Prime numbers and integers

1 is not a prime. 2 is the smallest prime and the only even prime.

An integer is any counting number including negative numbers (e.g. -3, -1, 2, 7…but not 2.5)

## Fast Fractions

i.e.

## Divisibility

3 : sum of digits divisible by 3

4 : the last two digits of number are divisible by 4

5 : the last digit is either a 5 or zero

6 : even number and sum of digits is divisible by 3

8 : if the last three digits are divisible by 8

9: sum of digits is divisible by 9

## Combinations and Permutations

n is the total number, r is the number you are choosing

## Probability