The GMAT Quantitative Section is designed to test your quantitative reasoning—your ability to think logically about quant concepts. It covers basic math concepts, including arithmetic, algebra, and geometry, but it’s not truly a math test (though it can certainly feel like it). The section contains two problem types: Data Sufficiency and Problem Solving.
You will need to relearn many of the quant skills you first learned in high school (or earlier!). And you’ll need to learn strategies for approaching the two problem types, Data Sufficiency and Problem Solving, as efficiently as possible.
Finally, you do not get a calculator on the Quant section of the GMAT—so you will have to do your math work by hand.
What is the breakdown of GMAT Quant questions?
- Time limit: 62 minutes
- Number of problems: 31
- Average time per problem: 2 minutes
- Problem types (typical number): Data Sufficiency (~13–14) and Problem Solving (~17–18)
You’ll have 62 minutes to answer 31 Quant problems, or an average of 2 minutes per problem.
The two problem types, Data Sufficiency and Problem Solving are mixed throughout the section; they can come in any order. You can expect to see about 13 to 14 Data Sufficiency problems and about 17 to 18 Problem Solving problems on the GMAT.
What math skills are tested on the GMAT?
- Arithmetic, including number properties, percents, fractions, and ratios
- Algebra, including exponents, linear equations, quadratics, and functions
- Statistics, including mean, median, and standard deviation
- Geometry, including lines and angles, polygons, and circles
Problems may be written in “pure math” form or in “story” form, so you’ll also need skill in translating a story into the necessary math concepts to solve.
While you do need to know various rules and formulas, the GMAT is explicitly designed to allow you to take advantage of shortcuts—estimation, testing out a few real numbers, and so on. The GMAT isn’t all that interested in precise calculations; rather, the test mimics the real-world usage you can expect in business school and the working world.
For example, business schools are interested in knowing whether you understand quant concepts well enough to do some quick back-of-the-envelope calculations to determine a rough answer to the CEO’s question—7,500 is good enough; 7,462.39 is unnecessary. Or whether you are able to realize that the sales forecast numbers your coworker just handed you don’t make logical sense—even though you haven’t performed the precise calculations yourself.
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How data sufficiency works
Data Sufficiency, or DS, problems present you with a question and two statements—but they’re not actually asking you to solve the math. Rather, they’re asking you to determine what information would be sufficient/necessary to allow you to do the math…if they asked you to do it.
These are a little confusing at first, but the beauty of DS is that you don’t have to actually do most of the math—and you can still solve the problem.
Data sufficiency GMAT practice question
The first line is the question stem:
If Farai is twice as old as Dmitry, how old is Farai?
This question stem is both asking a question (how old is Farai) and providing a fact that you can use when evaluating the problem (Farai is twice as old as Dmitry).
The next two lines are the two statements:
- Samantha is 4 years younger than Dmitry.
- Samantha will be 11 years old in 5 years.
Finally, there are five answer choices that encompass the five possible ways you could combine the two statements to be able to calculate an answer to the question. Here’s the shorthand for each answer choice:
(A) Statement (1) works by itself, but statement (2) does not.
(B) Statement (2) works by itself, but statement (1) does not.
(C) Neither statement works by itself, but they do work together.
(D) Each statement works by itself.
(E) Even using both statements together, you can’t answer the question.
These five answer choices are always exactly the same and always given in the exact same order—so you don’t even have to read them on test day. By the time you get to the test, you’ll just know what they are.
First, jot down the fact given in the question stem, as well as the question itself:
F = 2D
F = ?
Pause for a second, What would you need to know in order to be able to solve for F? In this case, if they tell you the value for D, then you can find the value for F. So add a second question to your notes:
F = 2D
F = ? or D = ?
If a particular piece of information allows you to find a unique value for either F or D, then that information is sufficient. On the other hand, if a piece of information doesn’t allow you to find any values for F or D or it gives you multiple possible values, then that information is not sufficient to answer the question.
Next, glance at the two statements and choose one to start. On this one, for example, you might choose to start with statement (2) since it only mentions a third person, Samantha.
Statement (2) does allow you to figure out how old Samantha is today, but that’s irrelevant to the question, since it doesn’t tell you anything about F or D (at least, Samantha’s age is irrelevant without more information…). So statement (2) is pretty quick to evaluate: It is not sufficient to answer the question.
Answers (B) and (D) both say that statement (2) is sufficient to answer the question, so eliminate choices (B) and (D).
Next, look at statement (1)—and only statement (1). Forget that statement (2) exists. (You’ll learn why in a minute.)
Statement (1) by itself provides a relationship between Samantha’s age and Dmitry’s age. But it doesn’t provide an actual age for anyone—not Samantha or Dmitry or Farai. So this statement by itself isn’t sufficient to answer the question; eliminate answer (A), which says that statement (1) works by itself. (If you hadn’t already eliminated answer (D), you could also eliminate that answer now.)
Finally, look at the two statements together. Statement (2) allows you to find Samantha’s current age. Once you know Samantha’s age, you can plug it into Statement (1) to find Dmitry’s age. And knowing Dmitry’s age is sufficient to allow you to find Farai’s age—so using the two statements together, it is possible to answer the question.
Answer and Explanation
The correct answer is (C). Neither statement works by itself, but they do work together.
You can only choose this answer if you have first determined that each statement does not work by itself. That’s why, earlier, you had to forget about statement (2) and just look at statement (1) by itself.
On this problem, the two statements do work together, so the answer is (C), but if even putting the two statements together doesn’t provide enough information to answer the question that was asked, then the correct answer to the problem would be (E).
By the way, how old is Farai—what’s the actual number? No idea. Don’t waste time calculating; you don’t need to do that in order to find the correct answer to a Data Sufficiency problem.
It takes some time to wrap your brain around Data Sufficiency—practice these every day for two to three weeks until you get used to the structure and organization of the statements and answer choices.
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How problem solving works
Problem Solving (PS) is the classic multiple-choice math problem: They give you some info, they ask you a question, and they give you five answer choices with numbers or variables in them.
Unlike DS, you are actually going to have to solve the math to get to the answer. But PS will at least feel a lot more familiar right from the start.
Be careful, though! Because PS problems feel more familiar, you’re going to be more tempted to use the textbook solution methods you learned in school. But a lot of PS problems can be solved much more efficiently by using various test-taking strategies—estimating, testing out some real numbers, trying the answers.
Standardized tests are literally built (on purpose!) for you to take advantage of these strategies to save time. In fact, someone who tries to solve all of the math problems in the “old school” way will most likely run out of time before they can finish the test. The GMAT is not really a math test. In the real world, it’s good enough to know that revenues were up approximately 10% this quarter; if you take the time to calculate and tell your boss that revenues were up 9.843% this quarter, she’s going to think that you’re wasting your time.
How to train yourself to think like an executive
As you get ready for the GMAT, train yourself out of your “old school” mentality and into your “executive mindset” mentality: What’s the quickest, easiest way to get to the answer—without making a mistake?
Problem solving GMAT practice question
At a particular school, 65% of the students have taken language classes. Of those students, 40% have studied more than one language. If there are 300 students at the school, how many have studied more than one language?
First, read the question and jot down the information given:
- 300 total
- 65% → LC (abbreviation for language class)
- 40% OF 65% → more than one LC
Glance at the answers (before doing any work.). They’re pretty spread apart, indicating that you can estimate at least a little.
The first step is to figure out how many students take language classes. 65% is a little less than two-thirds (or 66.7%), so use two-thirds to estimate. Two-thirds of 300 is 200, so approximately 200 students have taken language classes.
Is that value, 200, a little bit of an overestimate or a little bit of an underestimate?
Because the real percentage (65%) is a little less than the percentage actually used (two-thirds, or 66.7%), the value of 200 is a little bit greater than whatever the exact 65% figure would be. In other words, 200 is a little bit of an overestimate.
Next, here’s the source of one of the trap answers. The 40% who have taken more than one language class is not 40% of the total number of students. Rather, it’s 40% of just the 65% who’ve taken language classes. So the next step is to take 40% of the 200 figure.
That’s not a terribly hard calculation to do…but get out of your “old school math” mindset. Don’t do calculations that you don’t absolutely have to do! 40% is less than 50%, so 40% of 200 has to be less than 100.
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How GMAT Scoring Works
The GMAT Quantitative section is scored on a scale from 6 (low) to 51 (high). Most schools want to see a score of at least 40 and the most competitive schools are typically looking for a Quant score of 45 or higher.
Your Quant and Verbal scores are also combined into your Total score, which ranges from 200 (low) to 800 (high). The Total score is the score that schools care about most (followed by your Quant score, for most schools). An average GMAT score is about 570; top-10 business school programs report average scores for their students in the 710 to 740 range.
Review What’s a Good GMAT Score to learn how to determine what kind of goal score will help to make you competitive at your target programs.