Unlike traditional multiple choice problems, these questions are not asking you to “solve” for an answer. Instead, you are given two quantities and tasked with determining how these two quantities relate to one another.

The fours answer choices will always look the same:

A. Quantity A is greater.

B. Quantity B is greater.

C. The two quantities are equal.

D. The relationship cannot be determined from the information given.

Memorize these. There’s no reason to waste precious seconds reading the answer choices when they are always the same for the Quant Comparison questions.

In order to be able to choose an option such as A, we need to know that A is always greater than B. If A is only sometimes greater than B, we must choose D as our answer.

Here’s an example Quantitative Comparison problem that deals with properties of numbers:

First, we look to the given information. a^{2}b < 0 says that a squared number (which must be positive: try -3^{2} and you’ll get positive 9) times b is less than zero. We can glean from this that b must be negative. Next, we look at ab^{3} > 0. We already know that b is negative, and a negative number cubed remains negative; thus, a must also be negative.

Since both a and b are negative, but we don’t know which variable is more negative, our answer must be D.

A video explanation of this problem can be found on Book Smart Prep’s IGTV channel.