# GRE Quantitative Comparison - Tactics

There are many ways in which you can attack a quantitative comparison question, when confronted on one on the GRE exam. To get a feel for the types of questions that you should expect, practice on as many practice questions as you can. A few tactics are given here.

- If there are equations or variables in either of the columns, then you can try and substitute numbers for the variables to see if you can come up with a relationship that answers the question. For example, consider the following, shown previously in this tutorial:

*x*is a non-negative integer.**Column A****Column B***x*2 *x*

Plug in values

*x*= 0 and*x*= 1, and in one case you'll get that Columns A and B are equal, and when*x*= 1, then you'll get that Columns A and B are not equal. In that case, the answer HAS to be 'cannot be determined'. - You can also try to break the relationship or try to determine if the values in both columns must necessarily be equal or not. For example:

Two sides of a triangle **T**are 3 and 4**Column A****Column B**The third side of **T**8

In order to solve this question, you have to recall a few things about triangles. Namely, that the length of a side of a triangle cannot be larger than the sum of the two other sides of the triangle. Here, sides one and two are 3 and 4, for a total of 7, and so the third side CANNOT be larger than 7. Right away, then, you know that the value in

**Column B**is larger. - Finally, as is the case with most of the math questions on the GRE, if you get stuck with doing overly long calculations, then STOP! Remember, the GRE is not a test of you calculation skills; instead, the math section is meant to gauge you math skills. If you find yourself doing long calculations, then stop and take a closer look at the question. Most likely, there is a shortcut that you didn't see and which the GRE test makers are trying to determine if you can figure out. For example:

**Column A****Column B**(2432)(768) (1216)(2)(800-32)

Don't do the calculations, but instead notice that the values in Column B can be rewritten to be the same as in Column A. (1216)(2) = 2432, and (800-32) = 768, so Column B = (2432)(768).