CHAPTER 22

Math Formulas on the GMAT

Learning Objectives

After studying this chapter, you will be able to: 

• Identify questions that require the use of commonly tested math formulas
• Translate a word problem into the appropriate formula and solve for the unknown value
• Apply the Kaplan Methods for Problem Solving and Data Sufficiency to a variety of questions that involve formulas

Below is a typical Problem Solving question dealing with a commonly tested math formula. In this chapter, we’ll look at how to apply the Kaplan Method to this question, discuss the common math formulas tested on the GMAT, and go over the basic principles and strategies that you want to keep in mind on every Quantitative question involving math formulas.

1. If the average (arithmetic mean) of x, 25, y, and 30 is x + y, which of the following equals the value of x?
   1. 
   2. 
   3. 
   4. 
   5. 

Before you move on, take a minute to think about what you see in this question and answer some questions about how you think it works:

• What math formula is being tested in this question?
• What does the format of the answer choices tell you about your task?
• What can you infer about how the GMAT constructs questions based on common math formulas?
• What GMAT Core Competencies are most essential to success on this question?