a letter to GMAT algebra
Happy Thanksgiving! If you can't find x (or don't really want to), please find some pumpkin pie instead.
GMATPrep Question Pack FAQ, part II: GMAT “fake tests”
(This is part two in a series on the GMATPrep Question Pack. If you’re interested in reading more about the basics of the GMATPrep Question Pack, please check out part one.) Q: What is the best way to use the quant questions in the GMATPrep Question Pack? Should I do the questions in order, or should I randomize them, or…?
A: Here comes a very long answer. Consider yourself warned.
If you want, you could just do the questions in order, the same way you would use the GMAT Official Guide or any other GMAT test-prep book. But I think it’s better to compile the GMATPrep Question Pack exercises into what I call “fake tests,” since there’s a desperate shortage of computerized practice tests that use actual, retired GMAT questions.
Here’s how it works: for quant, select the questions that you think are appropriate for your level. If you’re struggling on the quant section of the GMAT, maybe you should stick with the easy and medium questions. If you’re consistently scoring in the mid-40s or above on the quant section, then you should probably select all of the medium and hard questions, as shown below. And then hit the buttons for “random” and “study” mode.
This will give you a nice, randomized selection of questions, vaguely approximating the feel of the actual GMAT exam. This isn’t a perfect approach, since the actual GMAT is adaptive, and the GMATPrep Question Pack “fake tests” are randomized. But to be honest, the actual GMAT exam often feels pretty darned random, and if you select your GMATPrep Question Pack difficulty levels correctly, the 37-question “fake test” will feel very much like an actual GMAT exam.
The only problem is that you’ll have to set your own timer for 75 minutes, and you’ll have to stop yourself when you’ve completed 37 questions. The software won’t do it for you. That’s annoying, but easily fixed with the help of a stopwatch or a kitchen timer.
Sure, this isn’t exactly the same thing as taking, say, a GMATPrep practice test. You won’t get a scaled score. But these “fake tests” will give you an opportunity to test your mettle on real GMAT questions, under timed conditions.
Even without a scaled section score, you can learn a ton from your mistakes. Did you make a lot of careless errors under time pressure? Did you have to scramble at the end of your “fake test” because you spent too much time on a handful of hard questions? Should you have been quicker to let the tougher questions go?
If you answer “yes” to any of these questions, you probably need to focus carefully on your timing and accuracy before you take the actual GMAT exam. So the GMATPrep “fake tests” aren’t exactly perfect, but they’re still an outstanding tool for improvement if you’re diligent about analyzing your errors and your timing.
Q: What about verbal? How should I use the verbal questions in the GMATPrep Question Pack?
A: On the quant side, I would argue that the GMATPrep Question Pack “fake tests” offer a reasonable facsimile of the actual GMAT experience. On the verbal side, I’m not so sure.
In theory, you could select a nice cross-section of GMAT sentence correction, reading comprehension, and critical reasoning questions, and then select “random” and “exam” mode, just as you would for the quant “fake tests.” And then you could do 41 questions in 75 minutes, and it would feel much like the actual GMAT. In theory.
Here’s the problem: there’s a little hitch in the GMATPrep Question Pack software, and if you select “random” and “exam” mode for reading comprehension questions, you’ll only receive one question for each reading comprehension passage, instead of the three or four questions that you would see on each RC passage on an actual GMAT exam. So you might see 10 or 12 or 15 reading comprehension passages in your “fake test”, and each of those passages would include only one question. Not fun.
The only alternative is to select “in order” instead of “random,” but then you’ll see an endless series of consecutive reading comprehension questions. And obviously, that isn’t realistic, either.
So the bottom line is that you can’t really do anything to produce semi-realistic verbal “fake tests.” And that’s a sad story. You can, however, skip the reading comprehension questions, and stick with critical reasoning and sentence correction only (in “random” and “exam” mode). You’ll probably have an easier time finishing 41 questions in 75 minutes when there aren’t any reading comprehension questions included, but at least you’ll be able to do something that resembles an actual test. If nothing else, you’ll get some good exposure to official questions, and your stamina will be vaguely challenged by the experience, especially if you do a quant section beforehand.
And then if you really want to do some extra GMAT reading comprehension practice, you can just do those questions in order.
Q: When should I use the GMATPrep Question Pack?
A: As I discussed in part one of this series, the GMATPrep Question Pack contains some of the newest official GMAT questions available, and it is definitely one of the best GMAT study resources out there. But it’s wise to avoid burning through the best materials too early in the study process, so you might want to make sure that your quant and verbal fundamentals are sound before you rip through all of your official GMAT materials, including the GMATPrep Question Pack.
At the very least, the GMATPrep Question Pack definitely isn’t the first resource you should turn to when preparing for the GMAT, and it makes sense to use it only when you feel 100% ready. For most of you, that means saving the GMATPrep Question Pack until the last few weeks before your actual GMAT exam.
Q: I finished a GMATPrep Question Pack “fake test” and now I can’t access the questions I completed! WTF?
A: Yeah, welcome to the wonderful world of janky GMAC software. (And yes, I’m proud that I managed to use the word “janky” on a GMAT blog.)
I also mentioned this in part one of this series, but it’s always a good idea to take screenshots of the questions you missed immediately after finishing anything in the GMATPrep software, including both the “real” GMATPrep tests and the GMATPrep Question Pack “fake tests.” It’s annoying, but it’s also the only way to be 100% certain that you don’t miss an opportunity to review the questions.
GMATPrep Question Pack FAQ, part I: the basics
The new GMATPrep software and the $25 GMATPrep Question Pack have been around for nearly a year now, but I have a funny feeling that the GMATPrep Question Pack is still somewhat underutilized as a GMAT study resource. So in an effort to encourage you to use the GMATPrep Question Pack—and to use it wisely—here are answers to a few questions that I’ve been asked about it over the past year or so. This is the first part of a two-part series; I’ll post part two next week.
Q: Does the GMATPrep Question Pack actually contain new questions, or do the same questions appear in the GMAT Official Guide or somewhere else?
A: Let’s face it: GMAC has a funny habit of selling recycled questions. The (rather expensive) GMAT Focus tests overlapped the GMAT Official Guide and the GMAT Quant Review Guide, and GMAC still sells crusty old GMAT Paper Tests that are filled with questions that appear elsewhere.
But the GMATPrep Question Pack seems to contain good, fresh, retired questions, and the official GMAT blog insists that the GMATPrep Question Pack exercises don’t appear anywhere else. So I think it’s safe to say that the Question Pack really does contain completely new questions. Pretty exciting.
Q: Is the GMATPrep Question Pack worth the money?
A: Absolutely. I’m completely convinced that there is no substitute for good, official GMAT questions. They’re infinitely more valuable than “knockoff” materials produced by GMAT test-prep firms. So you don’t want to pass up any opportunity to practice with real, retired GMAT questions.
Considering that you’ll pay $250 just to take the GMAT—and considering that you’re likely to invest more than $400,000 in an elite MBA if you include the two years of forgone wages—$25 for a set of 404 official GMAT questions is a pretty serious bargain.
Q: Does the GMATPrep Question Pack contain newer questions than the Official Guide?
A: Presumably, yes. Although we don’t know exactly when the GMATPrep Question Pack exercises were actually retired, it’s probably safe to suspect that the questions are relatively new. Some of the GMAT Official Guide questions are also fairly new, but others are at least 20 years old, and have appeared in several editions of the GMAT Official Guide.
Q: Does the GMATPrep Question Pack include answer explanations?
A: Yup, it does, though I should warn you that the explanations don’t always offer the easiest way to do each question. But the same is true of the GMAT Official Guide, and I think we’ll all agree that a slightly flawed explanation is far better than no explanation at all.
Q: How hard are the questions in the GMATPrep Question Pack?
A: Well, the questions are divided into “easy,” “medium,” and “hard” categories, and I think those labels are reasonably accurate. Some of the “hard” questions are absolutely brutal, and they’re a good representation of the nastiness that you’ll see on the actual exam if you’re doing well. So there’s something for everybody in the GMATPrep Question Pack, even if the “easy” questions are unlikely to offer a very good workout for anybody with 700-level GMAT skills.
In case you’re curious, the GMATPrep software includes 90 questions for free, an addition to the 404 questions that are sold for $25. Out of the grand total of 494 questions, 146 are “easy”, 199 are “medium,” and 149 are “hard.” So even if you completely ignore the “easy” questions and the questions that you would get for free, you’ll still have an additional 300 “medium” and “hard” questions. And that’s a pretty good deal for $25.
Q: Will I see any of the GMATPrep questions on the actual exam?
A: Sorry, no. You’ll see a completely fresh set of creative, difficult GMAT questions that aren’t published anywhere else. So learn everything you can about the concepts underneath the GMATPrep questions, and learn how to approach completely new questions. Because you’ll see plenty of them on your actual GMAT exam.
Q: Why can’t I review the GMATPrep questions anymore? I did them, but I can’t access them in the same order. WTF?
A: Yeah, the nice people at GMAC are really great at writing standardized tests, but they apparently aren’t very good at developing software. There are all sorts of goofy glitches and quirks in the GMATPrep software, including some bizarreness when it comes to reviewing the questions you already finished.
The best advice? Immediately after completing any questions from the GMATPrep software, take screenshots of them, regardless of whether you’re doing an actual practice test or just the Question Pack. It’s the only way to be 100% certain that you don’t lose an opportunity to review the questions after completing them.
stealth exponents
It's always a little bit tricky and annoying to write math problems on a GMAT blog (there's no way to comfortably write equations, unless you want to import images), but I'll do my best with this topic. I just want to make a few little comments about exponents, and about the ways in which the GMAT Official Guides (including the GMAT Quantitative Review Guide) can lull a perfectly good GMAT student into complacency on the topic. Hopefully, you know all of the basic exponent rules. If you're multiplying two terms with the same base, you'll add the exponents (example: x^3*x^4 = x^7). If you're dividing, you know that you subtract the exponents, and then you might encounter something like a "power of a power" question (example: (x^6)^2 = x^12). If you know these rules and a few other basics (i.e. what happens if an exponent is negative, a fraction, or zero), you'll be fine on the GMAT. Right?
If you're focused on the GMAT Official Guide questions... well, yes, you'll be mostly fine. Let's take a quick survey of the exponent questions in the problem solving section of the 12th edition of the GMAT Official Guide: #15, #28, #46, and #108 all contain exponents, but they're mostly a matter of calculating (or simplifying) some numbers. #104 and #110 look like exponent problems, but both are really about factors, not exponent properties. #137 could be solved using exponent properties, but is just as easily done with some simple calculations and logic...
I could go on. My point is, most of what you encounter in the GMAT Official Guides doesn't require much knowledge of exponent properties. And when you do need to use exponent properties, they're just covering the basics.
Funny, I didn't see anything basic last time I took the GMAT, and neither did most of my students who scored above 600. I keep hearing the same refrain: the exponent problems looked nothing like they do in the GMAT Official Guides.
I'm convinced--based on the GMATPrep, GMAT Focus, and the real thing--that the GMAT is much more likely to show you an exponent question that has something to do with factoring and/or "base conversion." Neither of these topics necessarily receive the attention they deserve in GMAT test-prep books.
Please accept my profuse apologies for the crappy notation, but here are a couple of examples of realistic, harder exponent problems (NOT from official GMAT materials, lest I incur the wrath of some bigshot NYC lawyer sent by the bigshots who write the GMAT):
(7^10 - 7^8)/3 = (2^x)(7^y). If x and y are integers, then what is the value of x + y?
3^(x-1) - 3^(x+1) = -(9^5)(2^3). What is the value of x?
I'm not going to post solutions until I'm begged repeatedly, but hopefully you see where I'm going with this. You're going to see GMAT exponent problems that require some factoring, as well as the ability to make some ostensibly unlikely connections. Unless you've seen these problems, you might be wondering where the heck the 2's are coming from.
Welcome to the GMAT. If you're not uncomfortable, you're probably not doing well. Either that, or you're way smarter than I am, and you shouldn't be wasting your time reading a blog posting about exponents on the GMAT.