GRE Percent Change Questions

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Manhattan Prep GRE Blog - GRE Percent Change Problems by Neil Thornton

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One of the most common mistakes many students make on the Quant section of the GRE is to misread percent questions, especially ones that ask you to calculate percent change (i.e. increase, decrease, more, less, greater, discount, or profit). You can fix this issue with a bit of practice, but it requires some careful reading on your part.

Even with easy numbers, GRE percent change questions can get pretty tricky. Given two numbers, 6 and 8, you might be faced with many questions, all related, but with very different answers.

6 is what fraction of 8?
8 is what fraction of 6?
6 is what percent of 8?
8 is what percent of 6?
8 is what percent more than 6?
6 is what percent less than 8?

To get a clear mental picture of these questions, picture two stacks of bricks, one with 6 bricks and one with 8 bricks.

How are they related to each other? Which one is shorter? Taller? What’s the difference between them? With a quick glance at your mental image, you can see that the 8 is bigger and there’s a difference of 2 bricks. That’s no problem.

Fraction Of

When faced with “fraction of” or “percent of” questions, whatever method you’re comfortable with will probably work here. You might have learned “is/of” or “part/whole,” and as long as you keep track of which one is bigger, you should be okay.

6 is what fraction of 8?

6/8 = ¾

8 is what fraction of 6?

8/6 = 4/3 or 1 ⅓

Percent Of

For “percent of” questions, my preferred method is “translation,” in which you turn English words into math symbols:

Is: =
Of: * (multiply)
What: x, z, q (any variable)
Percent: /100

6 is what percent of 8?

Translate: 6 = x/100 * 8 and solve: x = 75
Or, just do 6/8 = .75 or 75%

8 is what percent of 6?

Translate: 8 = x/100 * 6 and solve: x = 133 ⅓%
Or, use is/of = 8/6 = 1.3333 (repeating) so 133 ⅓%

Percent Change

NOW, SLOW DOWN! Here’s where the GRE can get tricky! Pay attention to what the question is asking. If the GRE asks you to calculate the “percent change,” you have to alter your approach.

8 is what percent more than 6?

Think about the difference between the two. Which one is more? 8 is 2 more than 6, or:

6 + 2 = 8

The GRE is asking you about that difference! SO if the question asks “percent more than 6,” the question is asking, “What part of 6 is the difference (2)?”

Confused? Don’t be. Just repeat the following mantra: “Put the change over the original” or:

Manhattan Prep GRE Blog - GRE Percent Change Problems by Neil Thornton

So in this case, to get from 6 to 8: the change (difference) is 2 and the original is 6. (When you increase, the original was smaller). So:

2/6 = 1/3 or 33 ⅓%

If you’re having trouble figuring out which one is the “original,” you can make yourself a flashcard.

Percent increase = change/smaller
(Or percent more, greater, profit)

6 is what percent less than 8?

Once again, the difference is 2, but the original is now the bigger of the two numbers. So:

Change/Original = 2/8 or ¼ or .25 or 25%

One more flashcard:

Percent less = change/bigger
(Or percent decrease, loss, discount, etc.)

Summing Up

For questions that ask you to calculate GRE percent change, all you really need to do is memorize “change over original” and think twice about which one is the original. Note: “percent more” and “percent less” are two different questions with two different answers!

% Change = change/original
% Increase = change/smaller (original is smaller)
% Decrease = change/bigger (original is bigger)

Try this one on your own!

A clothing store purchased a dress wholesale for $80 and sold it for $200. What was the store’s percent profit on the wholesale price of the dress?
(Or: by what percent did the store increase the price of the dress?)

(A) 40%
(B) 66 ⅔%
(C) 60%
(D) 150%
(E) 250%

Faced with a “percent change” question, remember your mantra, “Change over original” and get to work.

The change from 80 to 200 is 120. The original price was 80.

In your calculator, put 120/80 and you’ll get 1.5 or 150%. So the answer is D!

There’s certainly more to percents than this, but learning how to handle “percent change” questions can help you throughout the test, especially on those tricky “Data Interpretation” questions (the charts and graphs). For more on percents, check out our “Fractions, Decimals, and Percents” GRE Strategy Guide or sign up for one of our classes! 📝


Want more guidance from our GRE gurus? You can attend the first session of any of our online or in-person GRE courses absolutely free! We’re not kidding. Check out our upcoming courses here.


Neil Thornton Instructor HeadshotWhen not onstage telling jokes, Neil Thornton loves teaching you to beat the GRE and GMAT. Since 1991, he’s coached thousands of students through the GRE, GMAT, LSAT, MCAT, and SAT, and trained instructors all over the United States. He scored 780 on the GMAT, a perfect 170Q/170V on the GRE, and a 99th-percentile score on the LSAT. Check out Neil’s upcoming GRE course offerings here or join him for a free online study session twice monthly in Mondays with Neil.

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