## Overview of GRE Math

# When drawing a diagram can help with solving GRE quant problems

Word problems in the Quant section give you information needed to solve a question in the form of sentences. Often it can be helpful to transfer this information into a diagram, which you can draw yourself to help you find the answer.

Consider the following question from the __Official Guide to the GRE__:

*Of the people in a certain survey, 58 percent were at most 40 years old and 70 percent were at most 60 years old. If 252 people in the survey were more than 40 years old and at most 60 years old, what was the total number of people in the survey?*

*1,900**2,100**2,400**2,700**3,000*

Your first reaction may be to write an algebraic expression to solve this question. However, try drawing the information into a figure. It might look something like this:

This will help you to see that the people between the ages of 40 and 60 are 12% of the people surveyed. You are also told that 252 people are between the ages of 40 and 60. Now it’s time to use an algebraic expression such as the following, in which “x” represents the total number of people surveyed:

12% of x = 252

12/100x = 252

x = (252 x 100) / 12

x = 25,200 / 12

x = 2,100

Therefore, answer choice B is correct.

The advantage of drawing such a figure is that it can make it easier to interpret the information you have been given in a question in the correct way. As long as you put the right numbers in the right places on your diagram, it cannot lie to you. When you are in a hurry on test day, it can be difficult to understand exactly what is the important information needed to solve the question you are looking at, particularly if English is not your first language. Diagrams help!

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