McGraw-Hill Education GRE 2019

(2^3 )^20 = 2^60

Now the values in both quantities are expressed with a base of 2. To determine

which quantity is greater, you simply need to determine which quantity has the

larger exponent. In this case, the exponent in Quantity B is greater, and the correct

answer is thus Choice B.

Strategy: Use the Implied Relationship Between the Quantities

The nature of Quantitative Comparisons is that there exists an implied algebraic

relationship between the two quantities. Because of this fact, when you are working

with Quantitative Comparisons, you can perform the same operations to both

columns, as long as the operation satisfies one of the following conditions:

■ Add or subtract the same value or variable to both columns.

■ Divide or multiply both columns by a positive value or variable.

■ Square or square root both columns, as long as you know that all the values

in the columns are positive.

3 x + 5y = 22

QUANTITY A QUANTITY B

A B C D

SOLUTION: Since the given information concerns the sum 3x + 5y, you should

manipulate the two columns to isolate 3x + 5y. First, subtract 6 from both

columns:

6 x + 10y + 6 52

−6 −6

6 x + 10y 46

Next divide both columns by 2:

6 x + 10 2 y 462

↓ ↓

3 x + 5y 23

Since you are told that 3x + 5y = 22, Quantity B is greater.

Strategy: Work Backward

In some Quantitative Comparison questions, you will be asked to compare an

unknown to a given value. In these situations, it is often helpful to use the given

value as a baseline for comparison. Look at the following examples:

6 x + 10 y + 6 52

166 PART 3 ■ GRE QUANTITATIVE REASONING

02-GRE-Test-2018_107-172.indd 166 13/05/17 11:06 am