Tag Archives: GMAT quant

Misplaced Math Anxiety: The Evil Four

As an independent GMAT tutor with an unorthodox streak, I tend to be the GMAT resource of last resort for many test-takers. The majority of my NYC students have already taken at least one GMAT prep course, and most have taken the test at least once (one of my students took the test seven times before she called me, and cracked 700 for the first time ever this weekend… yay!). I love the challenge of trying to help students beat the GMAT after they’ve already exhausted every other resource, and I’m always honored when somebody puts their faith in me after months–or years–of falling short of their score goal.

Because the prospective students who contact me tend to have so much GMAT experience already, I usually ask the same question: what do you think is holding your GMAT score back? As you might guess, I get a huge variety of answers, but there’s one common thread: nearly everybody blames combinatorics, probability, rates, and/or overlapping sets for at least part of their struggles on the quant section. Let’s call those four topics the Evil Four.

I’m not going to tell you that rate questions aren’t important. I’m not going to tell you that combinatorics, probability, and overlapping sets aren’t important. But I will tell you that the Evil Four are never the difference between, say, a 650 and a 700.

Here’s the thing: when you really look hard at the test, none of the Evil Four seem to appear all that often. It’s possible that you’ll see two rate problems, but it’s more likely that you’ll see only one. It’s possible that you’ll see a combined total of three probability and combinatorics questions, but it’s also possible that you’ll see exactly none–even if you’re doing well on the exam. And overlapping sets questions aren’t so common either: very few test-takers claim to see more than one or two of them.

Think of it this way: you might only see a grand total of four or five questions from the Evil Four on the actual GMAT. That’s only a tiny proportion of the 78 questions on the test, yet I routinely speak with people who seem to spend as much as 50% of their study time on these topics. But if the Evil Four appear in less than 10% of GMAT test questions, why is everybody so stressed out about them?

Honestly, I think that test-takers tend to focus on these questions because they’re so damned memorable compared with the rest of the questions on the test. You won’t necessarily remember the algebra questions (too boring), the arithmetic questions (too pedestrian), or the number properties questions (too abstract); the crazy rate questions with two trains headed toward each other seem to stick in our heads much more easily. The unglamorous reality is that algebra (including word problems and functions), arithmetic (including word problems, percents, exponents, roots, and estimation), and number properties questions are the core of your GMAT quant score. If your accuracy on these three topics is less than stellar, your GMAT score will also be less than stellar.

Again, I’m not saying that rates, combinatorics, probability, and overlapping sets aren’t worth studying. I just think that these questions cause a disproportionate amount of anxiety, and I think it’s crucial to keep them in perspective. If you’re trying to raise your GMAT score from, say, a 47 to a 51, you probably need to study the living hell out of everything. But if your goals and starting score are more modest–or if you need to substantially improve your composite score–don’t overemphasize this stuff.

At the very least, make sure that you don’t focus on the Evil Four at the expense of more important topics. If you need to make a big improvement in your GMAT quant score, spend the bulk of your time developing your accuracy on algebra, arithmetic, and number properties. Since those three topics appear in more than two-thirds of GMAT quant questions, it would be wise to keep them at the front of your mind as you create your GMAT study plan.

how to scare your GMAT tutor

I have no idea whether other GMAT tutors are the same way, but I usually watch my phone like a hawk when one of my students is taking the GMAT. I get pretty excited about the prospect of seeing somebody succeed after weeks or months (or years) of hard work. Unfortunately, the other side of it is that I’m always battling that nagging little worry that my student might not do as well as I’d hoped or expected.

Today, one of my favorite students here in NYC left me a very cryptic voicemail after his test, which made me worry a little bit. I was tied up with other GMAT students all afternoon, and didn’t have a chance to call back. A few hours later, I received an email from him. The subject line just said “GMATTED”. If you’ve read my blog in the past, you know that I use the term “GMATed” pretty often. It means “the GMAT f**ked me over.”

So yeah, he scared me. This guy definitely put in his work, and seemed like one of the most consistent, steady performers I’d ever taught. Some students’ scores bounce around wildly from day to day, and I pray for luck when they take the actual test; this guy, though, was rock-solid in all of his prep, and I was shocked that he got GMATed.

He didn’t get GMATed at all. He got a 690 (44Q/40V) on his first try, which is enough to keep him in the conversation at pretty much any b-school out there. Very, very good stuff. By “GMATTED,” he just meant that he was exhausted and could barely form a sentence.

Dude.  Please, don’t scare me like that again.

Fortunately, I’ve had a very gratifying run of great results from my GMAT students over the past couple of months. My magic number this fall seems to be 710–before Mr. GMATTED, three of my last four students managed to get 710s, and that’s always fun to see. Two of them were taking the GMAT for the very first time, and both did three-week “crash courses” with me. In one case, a student had already taken a Veritas course, and I just helped her fill in some holes. The other crash-course guy managed to make huge leaps on quant–he scored 37 on his first mba.com test, and a 47 on the real thing. Can’t beat that. Both of these students were extremely talented, so I’m not going to claim that three-week GMAT crash courses are generally a good idea… but it can work, when the stars align properly.

My absolute favorite success of the season–and possibly of all-time–was a guy that I’ll call Mr. P. Mr. P called me when I first moved to NYC last summer, and he’d already taken the GMAT three times over the course of about six months. He had done craploads of self-study, and had already worked his way through pretty much everything Manhattan GMAT has to offer.

Here’s the crazy thing: despite all of his hard work, Mr. P’s scores were flat as a pancake. Exam 1: 640/40Q/37V/6.0. Exam 2: 630/39Q/38V/6.0. Exam 3: 630/38Q/38V/6.0. I complimented him on his remarkable consistency, then threw the proverbial kitchen sink at him in an effort to shake things up. As with the venerable Mr. V, it was tough to find material that Mr. P hadn’t seen before, and that always makes life challenging and interesting if you’re a GMAT tutor looking for (relatively) painless ways to help a student gain points.

And guess what? Mr. P managed to scare me a few months later with a depressed-sounding voicemail. We’d shaken things up, all right: he jumped to a 44 on verbal, but his quant actually went down, leaving him with an unsatisfying score of 660. Ooops. Time to fire the GMAT tutor?

Here’s the good part: one month later, he rolled back in to Pearson for his fifth attempt at GMAT glory, and got his 710. There’s a guy who deserved every damned point of that 710, and it was a lot of fun to see him get it.

GMAT and GRE test center glitches

Disclaimer: I have no real point in sharing these stories, other than to scare you just a little bit for no good reason.

Pretty much everybody faces some serious time pressure on the GMAT quant section, and many people are forced to scramble on the verbal and AWA as well. So if you lose two minutes due to a computer glitch, it’s pretty maddening. Two minutes won’t destroy your score, but it might make you flustered and cause a cascade of problems.

In the past 12 months, at least five of my tutoring clients have been affected by test-center glitches. This past weekend, two of them–one in NYC, one in DC–had issues. In both cases, the dudes working for Pearson VUE (the company that runs the testing centers) had a hard time logging the test-taker back into the system after a break. In both cases, the students lost a couple of minutes for the quant section. Pretty crappy.

In another couple of cases, the testing center dudes accidentally shortened the test-takers’ breaks by failing to notice when the test-taker was finished with a section. When you’re ready for a break after a section, you’re supposed to tell the computer that you’re ready for a break, and then raise your hand so that you can be escorted out of the testing room. Supposedly, the “escort” didn’t notice when a couple of my GMAT students were ready, and a few minutes passed before the proctor noticed the test-takers’ flailing hands. It isn’t a big deal to have eight minutes instead of ten for your break, but it’s still annoying.

And then there are the computer glitches. In one case, the system crashed during a break, and somehow restarted with several minutes already elapsed in the quant section. (I can’t explain why these problems seem to occur between AWA and quant. GMAT hates you?) Another student faced a really bizarre glitch which prevented him from clicking on certain radio buttons–if I remember correctly, he was literally unable to select most of the answer choices, and had to click “next” with some questions unanswered. He complained at the testing center, but they couldn’t really do anything about it. I don’t think that he even finished the test. In both of these cases, the test-takers called GMAC every single day until they were allowed to re-take the GMAT for free.

Again, I have no real point here. I’m not trying to criticize Pearson VUE–generally, I think that the company does a solid job, and I’ve had good experiences in their test centers. (GRE is another matter–last time I took the GRE at a Prometrics test center, I used an old, flickering monitor which made my eyes hurt. By the time I left, I felt like I’d been staring at a strobe light for four hours, which made me a little bit crazy.) As a full-time GMAT tutor who watches students spend craploads of time and money on the MBA admissions process, it’s painful to see people get thrown off by these stupid glitches.  But human and computer errors happen, and all you can do is roll with the punches.  And if the glitches really affect your score, you can always bitch and moan until GMAC compensates you for the errors.

GMAT Focus quirks

For the most part, I’m a fan of GMAC, the company that produces the GMAT. I’ve spent a good chunk of the last decade working as an SAT, ACT, GRE, and TOEFL tutor, and I respect that fact that the GMAT is much more complicated, precise, and nuanced than any of the aforementioned exams. And GMAC is also fairly generous about publishing retired test questions; some of us whine about the GMAT OG’s lack of hard questions, but the official guides for GRE and TOEFL are far worse, offering only a handful of (ancient, moldy) practice questions. So while I generally think that GMAC does its job really, really well, they seem to have been a little bit sloppy with GMAT Focus lately.

In some ways, GMAT Focus is the best of the GMAT practice material. Sure, it’s overpriced ($25 for one test, or $65 for three… basically, you’ll pay almost $1 per question). And I think it’s weird that they sell the tests in groups of three–you can actually take the test four times before questions start to repeat. And you’re given only 45 minutes to complete 24 questions–a little bit odd, since you’ll ultimately need to get used to doing 37 GMAT questions in 75 minutes. But GMAT Focus still contains an impressive bank of difficult, fresh GMAT questions; I’m convinced that GMAT Focus questions are much closer to the real thing than any other practice resource available. If you’re serious about improving your quant score, GMAT Focus is absolutely not optional.

Unfortunately, the GMAT Focus questions are no longer all that unique. Many of them appear in the 12th edition of the official guide, and I have a funny feeling that even more will show up in the next edition of the Quantitative Review guide. So you might be paying $1 for questions that you’ve already purchased in another book. That’s really annoying, especially if you’re already paying for a GMAT tutor.

Even more annoying: the GMAT Focus might not be as representative of the real test as I once thought. For a long time, it seemed that the GMAT Focus would give you a pretty good idea of the composition of the quantitative section–specifically, GMAT Focus included a lot more tricky logic, combinatorics, and “creative algebra” questions than the official guides, and GMAT Focus seemed to be an extremely accurate representation of the actual test. Sadly, something might have shifted, at least a little bit. In the past month, several of my students (all with quant raw scores above 40) whined that the real test didn’t have any of the tough combination/permutation/probability questions that appear on GMAT Focus. It makes me wonder whether the GMAT Focus is becoming somehow less indicative of the actual test. Again, I find that a little bit irritating–if it’s actually true.

Here’s the strangest report of all: one of my GMAT students swears that he saw a GMAT Focus question on the real exam last weekend. He claims that the question was absolutely identical, with the same numbers and everything. He didn’t share the details of the question (that would be illegal), but I find that pretty alarming if it’s true. Is GMAC getting sloppy? Was the “retread” GMAT Focus question tossed back into the real test as some sort of experiment, or as a statistical control for other questions? Or was my student just hallucinating after a long, stressful few hours of test-taking?

Either way, it’s interesting. I still think that it’s worth spending $90 for all four GMAT Focus tests, but I couldn’t really blame a budget-conscious GMAT student who comes to a different conclusion.

you got GMAT-ed

I’m toward the end of my second full month of tutoring in NYC, and it’s been interesting to see how my GMAT students here differ from the gang that I taught in DC. I had an amazing range of students in DC, including a couple of people who started at or above 700, quite a few others who started in the high 300s or low 400s, and pretty much everything in between. My first group of NYC GMAT students, on the other hand, consists almost entirely of ass-kickers, gunning for something close to a 700. I’ve met two guys who have gone through every official GMAT question twice; both of them diligently kept notebooks of all of their mistakes, and still didn’t get the scores they wanted. Pretty much everybody else I’ve met has graduated from a Kaplan, Veritas, Princeton Review, or Manhattan course. With only one exception, all of my students have consistently scored in the 600s on the real GMAT, and in the 600s and 700s on practice test.

So all of these guys know the test really, really well. Generally, they start by asking questions about the tough stuff–combinatorics, hard rate problems, set theory, conditional probability, and the most vicious of sentence correction problems. Hardly any of these guys are the least bit worried about their algebra or arithmetic skills when they call me.

I have a few little files of “easy” GMAT questions, mostly consisting of basic algebra, arithmetic, and geometry. Eighth-grade level math, at most. Over the past few weeks, I’ve given the set to most of these veteran GMAT warriors.

How did they do? Well, one student got a perfect score, which is exactly what he should have done if he wants to get a 700. (I’m very proud of you, Mr. V. May the GMAT gods grant you a 750 and admission to the MBA program of your dreams.) Everybody else got ripped to shreds, missing somewhere between 15% and 30% of the questions. That would be fine on medium-to-hard (say, 600- or 700-level) GMAT questions, but nobody with dreams of Harvard or Stanford MBA programs should miss this kind of stuff.

Here are a few examples of reasonably easy questions that caused problems:

1. You drop a ball from a height of 16 meters. Each time you drop the ball, it bounces to a level half as high as its starting point. If you catch the ball after the fourth bounce, how far did the ball travel?
(A) 30 meters
(B) 31 meters
(C) 40 meters
(D) 41 meters
(E) 45 meters

2. If x and y are two-digit integers such that x < 40, which of the following is closest to the maximum possible value of xy ?
(A) 400
(B) 1,600
(C) 4,000
(D) 16,000
(E) 40,000

3. If the numbers 13/24, 9/16, 1/2, 2/3, and 5/8 were ordered from greatest to least, the middle number of the resulting sequence would be
(A) 13/24
(B) 9/16
(C) 1/2
(D) 2/3
(E) 5/8

I’m not sure that any of these questions are much more than 500-level questions, but some good GMAT math students screw these up regularly, just because they don’t read carefully, or because they rush through their calculations. Sometimes it seems that arithmetic and algebra questions cause 600+ scorers to immediately think “this is easy, I’m going to destroy this question in 25 seconds so I can move on to harder stuff”… and then they make a dumb mistake. I call this phenomenon “getting GMAT-ed.”

The GMAT writes questions specifically to test your precision, and they’re trying to get you to fall into traps by being imprecise or careless. If you don’t count the bounces carefully, you won’t get (E) for question 1. If you jump to conclusions on #2 (i.e. by misreading an inequality sign or by missing the word “two-digit”), you might not know that the answer is (C). There’s nothing magical about question #3, but it’s easy to get overconfident and make a calculation or comparison error. The answer, incidentally, is (B). Easily 30% of my 600+ students have missed a version of that last one, even though it’s just a simple comparison.

The moral of the story? If you read a math question and you think that it’s easy, watch your back. Don’t let overconfidence get in the way of your GMAT score. Check your answer twice–it’s always worth spending an extra 15 seconds to make sure that you haven’t done something silly.