GRE: Quantitative Comparison Samples

The Quantitative Comparison section emphasizes shortcuts, insight, and quick techniques. Long and/or involved mathematical computation is unnecessary and is contrary to the purpose of this section.

Remember that your answers will conform to the following:

  1. if the quantity in Column A is greater;

  2. if the quantity in Column B is greater;

  3. if the two quantities are equal;

  4. if the comparison cannot be determined from the information given.

Sample 1

Column A Column B
(.9)8 (1.01)4

In Column A, a fractional value (a value less than 1) is multiplied by itself many times. So its value becomes increasingly smaller. (For example, 1⁄2 x 1⁄2 = 1⁄4; 1⁄4 x 1⁄2 = 1⁄8, and so forth.) In Column B, a number greater than 1 is multiplied by itself; its value grows larger. So Column B is greater.

The correct answer is B.

Sample 2

Column A Column B
(-10)100 (-10)101

A negative number multiplied an even number of times will yield a positive product. A negative number multiplied an odd number of times will yield a negative product. Since Column A will be positive and Column B will be negative, A is greater.

The correct answer is A.

Sample 3

Column A Column B
.05 - .125 .1

Subtracting in Column A, you get .05 - .125 = -.075. Our difference is a negative number. Thus, the positive value in Column B must be greater.

The correct answer is B.

Sample 4

Column A Column B
a, b, c, all greater than 0
a(b + c) ab + ac

Using the distributive property on Column A to simplify gives ab and ac; therefore, the columns are equal.

The correct answer is C.

Sample 5

Column A Column B
a > 0
b > 0
c > 0
(3a)(3b)(3c) 3abc

Multiplying column A gives (3a)(3b)(3c) = 27abc. Because a, b, and c are all positive values, 9abc will always be greater than 3abc.

The correct answer is A.

Sample 6

Column A Column B
Number of prime numbers between 3 and 19 5

The prime numbers between 3 and 19 are 5, 7, 11, 13, and 17. The correct answer is C, since there are 5 primes.