** ***This tip on improving your GMAT score was provided by Brian Galvin at Veritas Prep.*

GMAT data-sufficiency problems, particularly yes/no questions, are some of the most deceptively simple on the test. But test-takers can do quite well on these problems if they employ a simple strategy. If you can use each of the statements provided to arrive at both a “no” and a “yes” answer to the question (NY), you’ve proven that the statement doesn’t give you enough information to answer the question definitively. So when you see a yes/no data-sufficiency problem, your goal should be to get to NY. Here’s what we mean:

Consider the question: Is x > y?

Two statements are provided:

(1) x/y > 1

(2) y = 12

The question comes with five answer choices, A through E, requiring test-takers to determine if one or both statements—alone or together—are sufficient to answer the question, or if both statements are insufficient and additional information is needed.

Statement 1 is a bit abstract, so you might want to put some concrete numbers into play to get a better feel for it. If you were to plug in x = 4 and y = 2, you’d satisfy that expression (4/2 is indeed greater than 1) and you’d get the answer “yes,” so you could confidently write the letter Y on your note board.

Now that you’ve gotten “Y,” your primary goal should be to find “N;” if you can do this, you’ll definitively prove that statement 1 is not sufficient to answer the question. To do so, you may need to consider some “unorthodox” numbers, but this strategy pushes you to do so. Under what conditions could x/y be greater than 1 but x be less than y? What if x were -4 and y were -2? That still gives you 4/2 > 1, but in that case x is less than y. You have your “no,” so now that you’ve found NY, you can rule out statement 1 as not sufficient.

Statement 2 should be easier to rule out (Y: x = 13; N: x = 11). And taken together, the statements rule out your “they’re both negative” way of getting to N, so the correct answer to this question is answer choice C: “Both statements together are sufficient, but neither statement alone is sufficient.”

More important, recognize that on yes/no questions, your goal with each statement should be to get one N and one Y so that you can prove a statement to be insufficient. By actively seeking out each of those answers, you’ll push yourself to try the unique/unorthodox types of numbers that tend to form the traps for so many test-takers, and you’ll pick numbers and perform mathematical work more efficiently. When a question asks a yes/no question, your goal should be to make it to NY. If you can make it there, you’ll be that much closer to a GMAT score that can help you make it anywhere—such as Cambridge, Mass., Palo Alto, Calif., or even New York, N.Y.

*Brian Galvin has studied the GMAT full time since 2006 as the director of academic programs for Veritas Prep. He received a Masters in Education from the University of Michigan and is the proud owner of a 99th percentile GMAT score.*

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**For more GMAT advice from Veritas Prep, watch “A Sure Way to Beat GMAT Data Sufficiency Problems”**