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# Archive | Formulas

## GMAT Math: The Uses and Abuses of Formulas

First, a few practice problems: 1) In the figure above, AC = BC = 8, angle C = 90°, and the circular arc has its center at point C.   Find the area of the shaded region. 2)  Employees at a company will vote for an executive team of five people from eight qualified candidates.  The […]

## Compound Interest on the GMAT

First, a few practice problems.  Remember: no calculator! 1) If \$5,000,000 is the initial amount placed in an account that collects 7% annual interest, which of the following compounding rates would produce the largest total amount after two years? (A) compounding annually (B) compounding quarterly (C) compounding monthly (D) compounding daily (E) All four of […]

## GMAT Quant: Difficult Units Digits Questions

First, a couple 800+ practice questions (yes, you read that right – 800+) on which to whet your chops. 1) The units digit of  is: (A) 1 (B) 3 (C) 5 (D) 7 (E) 9 2) The units digit of is: (A) 2 (B) 4 (C) 6 (D) 8 (E) 0 3) The units digit […]

## Three Algebra Formulas Essential for the GMAT

First, a few practice problems. 1) The numbers a, b, and c are all positive.  If , then what is the value of ? Statement #1: a – b = 3 Statement #2: = 7 2) Given that (P + 2Q) is a positive number, what is the value of (P + 2Q)? Statement #1: […]

## 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 […]

## Pythagorean Triplets to Memorize for the GMAT

Learn the most common solutions to the Pythagorean Theorem There aren’t many numbers you need to memorize for success on the GMAT Quantitative section, but knowing a few key Pythagorean triplets will save you a ton of time.  First, try these GMAT practice question: remember: no calculator! 1) In right triangle ABC, BC = 48 […]

## GMAT Coordinate Geometry: Distance Between Two Points

How do you find the distance between two points in the x-y plane?  First, try these practice questions. 1) What is the distance from (–7, 2) to (5, –3)? (A) 10 (B) 11 (C) 12 (D) 13 (E) 14 2) Consider the three points in the x-y plane: P = (8, 4), Q = (6, […]

## GMAT Quant: Difference of Two Squares

You may remember this formula, one of the sleekest factoring tricks in all of algebra: This formula, called “the difference of two squares” formula, is a favorite of standardized test writers.  A simple enough pattern: see if you can detect where it shows up in the following challenging problems.   1)  = (A) (B) (C)  […]

## Breakdown of GMAT Quant Concepts by Frequency

Magoosh’s very own Mike McGarry, GMAT/Math Teacher/Tutor/Foosball player extraordinaire, went through 5 different sets of Official GMAT Practice Material and tallied questions based on the subject material they tested to find the most common GMAT questions. Here are the samples of Official Material he used to figure out the GMAT Quant breakdown: 1.GMAT Official Guide […]

## Isosceles Triangles on the GMAT

The GMAT quantitative section asks, among other things, about geometry. One of the GMAT’s favorite figures is the isosceles triangle.  An isosceles triangle is one that has two congruent sides.  Knowing simply that about a triangle has profound implications for answer GMAT Problem Solving & Data Sufficiency questions.   Euclid’s Remarkable Theorem Euclid first proved […]