Teach Yourself the GRE CAT in 24 Hours
    GRE Home  >  Sample GRE Questions  >  GRE Quantitative Comparison Questions
 
GRE Essentials
Amazon.com
 
GRE/GMAT Math Review, 6th Edition
Peterson's Guides (ARCO)
  T E A C H    Y O U R S E L F

GRE Quantitative Comparison Questions — Format, Directions, and Sample

    
            Popular Here 
 GRE Format
 Analogy Sample
 Vocabulary Tips
 
 
Related Sites 
 GRE Writing Skills
 Model GRE Essays
 GRE Word Smarts
 
 
The Quantitative Comparison format is one of two basic ones used for GRE Quantitative (math) questions. This page lists key features of GRE Quantitative Comparison questions. It also provides the test directions for this question format, a sample question (along with a tip for answering it), and a detailed analysis of the sample.

GRE Quantitative Comparison — Format, Skills Tested, and Test Directions

Here are the key "specs" for GRE Quantitative Comparison questions:
HOW MANY: 14 questions

WHERE: In the 45-minute Quantitative Ability section, mixed with Problem Solving questions

FORMAT: Multiple-choice (you select one of 4 choices by clicking on an oval)

SKILLS TESTED: Your ability to reason quantitatively [list of specific areas covered]

DIRECTIONS: The following directions will appear on your screen just before your first Quantitative Comparison question (and you can access them while tackling any Quantitative Comparison question by clicking on the HELP button).
 
Directions: Each question of this type consists of two quantities, one in Column A and one in Column B. Compare the two quantities and indicate:
  • if the quantity in Column A is greater
  • if the quantity in Column B is greater
  • if the quantities are equal
  • if the relationship cannot be determined from the information given
In some questions, additional information pertaining to one or both of the quantities to be compared is centered above the two columns.
 
Any symbol appearing in both columns represents the same thing in one column as in the other.
 
All numbers used are real numbers.
 
To review these directions for subsequent questions of this type, click on HELP.

Sample Quantitative Comparison Question

The following question is typical of GRE Quantitative Comparison questions, although this one is more difficult than average; about 40% of GRE test testers would answer it correctly. Notice that this sample question includes centered information (above Column A and Column B) that applies to both of the quantities to be compared.
 
* b < a < -1*
Column A

a2 - b2

Column B

(3a + 3b)(2a - 2b)

    The quantity in Column A is greater.
    The quantity in Column B is greater.
    The quantities are equal.
    The relationship cannot be determined from the
    ......information given.

Quick Tip for Sample Question

In handling GRE Quantitative Comparison questions, you can sometimes manipulate one or both expressions to reveal the comparison. In this question, try factoring both quantities. (The expression in Column A is one of the test-makers' favorites: the difference of two squares.)

Analysis of Sample Question

To reveal the comparison, first express Quantity A in its factored form:
(a + b)(ab)
Notice the similarity between this expression and the one in Column B. Now factor out the constants (numbers) in Quantity B so that Quantity B more closely resembles Quantity A:
(3a + 3b)(2a – 2b) =

6(a + b)(ab) =

6(a2 - b2)

Now consider the centered information:
b < a < –1
In light of this information, (a2b2) must be a negative number. Multiplying a negative number by 6 yields an even smaller number (to the left on the real number line). Therefore:
6(a2b2) < a2b2
Quantity A must be greater than Quantity B. The first response is the correct one.

GRE Home | Top of Page | About 
 

 
GRE Writing Skills   |   Model GRE Essays   |   GRE Word Smarts   |   Personal Statements

 Copyright © 1997-2009 by Mark Alan Stewart. 
All rights reserved.