GRE Quantitative Comparison

This article takes up from where the one of 9th March left off. We will look at GRE QC questions from a slightly different perspective. The first three answer options can be modified by using “Always.”

The modified answer choices are as follows:

1. The value of Column A is ALWAYS greater than the Value of Column B.
2. The value of Column B is ALWAYS greater than the Value of Column A.
3. Both the values of Columns A and B are ALWAYS the same.
4. The relationship between Columns A and B values cannot be determined from the information provided.

Interestingly, this small change justifies the significance of the last answer option (D), i.e., whenever we find a single possible case when the ALWAYS greater or ALWAYS equal thing can be negated! Students are seen hesitating to mark the answer option D; in fact, they make that extra effort to cross-check before marking it and, in the process, waste time on a fairly futile task.

3] Look out for D!

What I mean by ‘look out for D’ is that when you see a Quantitative Comparison question involving variables, try to prove the answer D. The key is to look for numbers that would work differently from the previously used numbers. Let us take an example to elaborate on this approach.

y=2x+5

Now, in this question, if we assume then the value of, thus clearly, quantity B is greater than that of quantity A. So, the answer is B. But let us try some other number for x. We intend to look for any number that can negate our previous answer, i.e., quantity B is greater. Okay, so if I assume that both the quantities are equal, say we plug in the given equation:

Therefore, we get here when both quantities are equal, i.e., answer C. As quantity A is not Always greater, we cannot determine the exact relationship between quantity A and B. Thus, the answer is D!

Please try the following example using the above strategy:

q>1

A very interesting fact about this method is that when we cannot find any number that negates the answer using a previous number, the answer must be the previous one!

Let us take one example of this:

x=y+7

In this problem, if we assume that we get, Thus, quantity A is greater than B. Therefore, answer A. We cannot find any value of x that negates the above answer. Hence, the answer is 100% A.

We have a couple of other methods, such as “using the Inequality concept” as this is a comparison question and “plug in values in variables,” which help minimize the efforts in QC questions. Still, the above methods are most frequently useful in actual exams! All the Best! Do write in for any doubts.

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