QC Xray
Here’s a typical QC, complete with directions. Don’t attempt the question
just yet—we’ll get to it in just a bit.
Directions: Each of the following
questions consists of two quantities, one in Column A and one in
Column B. You are to compare the quantity in Column A with the
quantity in Column B and decide whether:
(A) The quantity in Column A is greater.
(B) The quantity in Column B is greater.
(C) The two quantities are equal.
(D) The relationship cannot be determined from the
information given.
In a question, there may be additional information,
centered above the two columns, that concerns one or both of the
quantities to be compared. A symbol that appears in both columns
represents the same thing in Column A as it does in Column B.



A certain bread recipe calls for
water, flour, and yeast to be mixed in a ratio of 4:5:2
ounces, respectively.
Column A

Column B

The amount of flour
needed to make 220 ounces of bread
according to the recipe

100
ounces


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

The directions are fairly selfexplanatory: You’re given two quantities
and asked to figure out whether one is definitely bigger than the other, if
they’re equal, or if you don’t have enough information to tell. The quantities
may be absolute numbers or may include variables—a difference of no small
importance when it comes to strategy, as you’ll soon see. Sometimes the test
makers will provide additional information above the columns as part of the
question, sometimes not. In this case, the additional information is the
sentence describing the ingredient ratios for the bread recipe. Any additional
symbols or variables provided mean the same thing for both quantities.
QC answer choices are always the same, so it pays to memorize them right
now. And notice the major difference between these questions and all of the
other math questions on the GRE: There are only four choices.
Hey, that improves your odds right there, even if you have to take a blind
guess. Of course, the purpose of this chapter is to help you keep blind guessing
to a minimum.