I have been a GMAT tutor since 2011. My methods enabled me to score a 770 on this challenging exam, and my students frequently break the 90th percentile. Below are a few features which help define my GMAT tutoring style. Also see my GRE Tutoring page (the GMAT and GRE are pretty similar).
• Emphasis on comprehension rather than memorization: Students often struggle to remember all the formulas and problem-solving techniques that the GMAT seems to require. I can help you understand the why, and not just the how. It’s a lot easier to remember what to do if you know why you’re doing it.
• Flexibility: A good GMAT tutor should be able to work within your mental framework rather than imposing something completely unfamiliar. My goal is to find explanations and methods that work for you, even if they aren’t entirely standard. This is particularly relevant for Data Sufficiency questions and certain Critical Reasoning question types.
• Candor: I will always emphasize what you are doing well, but I will also be frank when you are heading in the wrong direction. Our goal is for you to develop good GMAT habits and avoid bad ones. Often mistakes can be educational, but I will make sure we avoid those that just waste time.
Visit my testimonials page to get a better idea of what working with me is like.
Looking for a challenge? Below are a couple Data Sufficiency questions and solutions I have composed. They give you some insight into how I approach GMAT tutoring.
Jane recently went on a long walk, not necessarily at a constant speed. Was there a 5-hour interval during which Jane walked at least 5 miles?
(1) Between noon and 10 pm, Jane walked exactly 10 miles
(2) Between noon and 8 pm, Jane walked exactly 8 miles.
(A) Statement 1 alone is sufficient, but statement 2 alone is not sufficient to answer the question.
(B) Statement 2 alone is sufficient, but statement 1 alone is not sufficient to answer the question.
(C) Both statements taken together are sufficient to answer the question, but neither statement alone is sufficient.
(D) Each statement alone is sufficient.
(E) Statements 1 and 2 together are not sufficient, and additional data is needed to answer the question.
To see that Statement 1 is sufficient, imagine dividing the interval into two 5-hour intervals, one from noon to 5 pm, and one from 5 pm to 10 pm. If we try to argue that Jane walked less than 5 miles in both of these intervals, then she walked less than 10 miles from noon to 10 pm, contradicting the statement. So she walked at least 5 miles in at least one of them. With Statement 2, it is not hard to construct cases in which Jane does walk at least 5 miles in some 5-hour interval, but now we can also construct cases in which she does not. For instance, she can walk 4 miles from noon to 1 pm and 4 miles from 7 pm to 8 pm.
Some members of a certain state legislature own dogs. What fraction of the dog owners in the state legislature are Republicans?
(1) Every member of the state legislature is a Republican or a Democrat (and no one is both).
(2) The fraction of Republicans in the state legislature who are dog owners is twice as large as the fraction of Democrats in the state legislature who are dog owners.
(A) Statement 1 alone is sufficient, but statement 2 alone is not sufficient to answer the question.
(B) Statement 2 alone is sufficient, but statement 1 alone is not sufficient to answer the question.
(C) Both statements taken together are sufficient to answer the question, but neither statement alone is sufficient.
(D) Each statement alone is sufficient.
(E) Statements 1 and 2 together are not sufficient, and additional data is needed to answer the question.
If you think the two statements combined are sufficient, and that 2/3 of the dog owners are Republicans, you may have assumed that the state legislature contains an equal number of Democrats and Republicans. Indeed, 2/3 is the answer to the question if we make that assumption. However, the assumption is not justified (notice that Statement 1 isn’t specific enough), and if we construct state legislatures with various proportions of Republicans and Democrats, we can generate various answers to the question. To consider just one interesting example, what if the state legislature has 80 Democrats and 20 Republicans? Let x be the fraction of Democrats who are dog owners; hence 2x is the fraction of Republicans who are dog owners. This means we have 2x*20 = 40x Republican dog owners and 80x Democrat dog owners, for a grand total of 120x dog owners. Thus, in this case only 40x/120x = 1/3 of the dog owners are Republicans.
This result might seem counterintuitive: The fraction of Republicans who are dog owners is larger than the fraction of Democrats who are dog owners, so shouldn’t the fraction of dog owners who are Republicans be larger than the fraction of dog owners who are Democrats? Not necessarily–the key point is that even though the fraction of Republicans who are dog owners is greater, the number of Republicans who are dog owners might not be. It all depends on what the fractions are multiplied by. If the number of Democrats in the state legislature is far larger than the number of Republicans in the state legislature, then even when we multiply the number of the Democrats by a certain fraction and multiply the number of Republicans by a larger fraction, there might still be more Democrats in the resulting group. This would then mean that the fraction of that group who are Democrats is in fact larger than the fraction who are Republicans.