The GMAT Official Guides 2017 Edition - Part 1
The new Official Guide books have landed and Ive got the scoop for you!
In this multi-part series, Ill start by discussing additions and changes to quant sections for The Official Guide for GMAT Review 2017, a.k.a.the OG or the big book, as well as The Official Guide for GMAT Quantitative Review 2017, a.k.a.the quant review or the quant supplement. Ill follow that up with a discussion of the new verbal questions from the big book and the verbal review. Ill also be providing you with a list of the new questions, in case you decide to study from both the 2016 and 2017 editions.
If you havent already bought your official guide books, then buy these latest editionssince you have to buy books anyway, you might as well work from the latest and greatest.
If you have already bought the 2016 editions, theres no need to rush out and get the new books now. Only 15% of the questions have changed in the 2017 editions. If, later, you feel you want more, you can decide at that point whether you want to get the 2017 edition books or whether you want to get some other official-source questions, such as the GMAT Prep Question Pack or GMAT Focus.
In the big book, chapters 1 through 4 have not changed. Chapter 3 is a Diagnostic test consisting of the same 100 questions that were in the book last year. In this installment, well concentrate on chapters 5 (Problem Solving, PS) and 6 (Data Sufficiency, DS), as well as the quant review book.
I did not spot any major differences in terms of specific content areas: there were no distinct trends in terms of dropping or adding a higher proportion of a certain kind of math. (If you look at just one of the two books, you might think so but if you aggregate the data across both books, there arent any big trends.) I did spot some other interesting tidbits that I'll share below.
Note: I cant reproduce the text of questions for copyright reasons, but Ill cite the problem number of any question I discuss so that you can look it up if you do decide to buy the book.
Whats new in Problem Solving for the 2017 editions?
In the big book, there are 35 new PS problems; the quant review contains 26 new PS problems. (The books also dropped an equivalent number of questions in each category.)
As we saw last year, the lowest-numbered new problems really do just require you to have the basic computation skills. Take a look at problems 2 and 5 in the big book or problem 1 in the quant review.
I was struck, though, by how very quickly you can start using test-taking strategies (working backwards, smart numbers, estimating), even on lower-level problems. Problem 7 in the big OG is a classic smart numbers problem, and both 13 and 19 can be solved by working backwards. In the quant review, you can eliminate answer choices for 10 and 11 by working backwards and estimating, respectively.
And that trend continued even as the question numbers got higher / the questions got harder. The classic test-taking strategies can be used over and over again, usually to get you all the way to the correct answer (though sometimes as a way to narrow down answers before guessing).
Ive long maintained that I would refuse to take the GMAT if I werent allowed to use test-taking strategiesthat is, if I were forced to use textbook math only. After seeing this years new problems, Im doubling-down on that pronouncement. The GMAT is a test of your quant reasoning skills, but it is not a math test. If you approach it like a classic school math test, you will not reach the highest scoring levels on this test.
Speaking of the higher-levels, the new higher-numbered PS problems always have ways to avoid very tedious math computation. Every single time! That is, if youre looking for those opportunities ... Problems 116 and 140 in the big book are basically ridiculous as pure math problems, but they can be solved much more easily via other methods. (More on these below!)
I was very happy to see that the two new probabilities questions (one PS and one DS) in the big book were much more about how probability works in general and less about having to perform confusing calculations. Just another data point to reinforce the we want to know how you think about math message. They know the MBA is not a math degree and they know you will never be asked to perform paper math in the real world.
Whats new in Data Sufficiency for the 2017 editions?
The big book contains 26 new Data Sufficiency (DS) problems; the quant review has 19 new DS. (The books also dropped an equivalent number of questions in each category.)
The books now use continuous numbering, meaning each new chapter does not start back at question #1. The DS problems in the big book are numbered 231 to 404.
In general, as the question numbers increase within one chapter, the questions get harder, so just note the starting and ending question numbers to help you gauge difficulty. In the big book, a DS problem numbered in the 200s is on the easier to medium side. A problem in the 300s is medium or hard. (And those last few in the low 400s are the hardest!)
In the quant review, the DS questions now run from 177 to 300, so the upper 200s are the harder ones here.
As with PS, you can use test-taking strategies all over the place on DS. Testing Cases, in particular, is everywhereand you can sometimes shortcut the process by testing number properties (characteristics of a number) rather than real numbers. Most of the time, using theory is even faster than testing real numbersas long as you are totally comfortable with the theory. If not, test real numbers instead.
In the big book, I was particularly intrigued when I hit problem 310. Weird problem, clever solution (more below). And then later in the same chapter, I hit another problem that used similar principles, even though they dont play out in the same way. (In fact, I ended up classifying the second one in a different content area entirely.) Next time, Ill tell you what the second problem is and how theyre similar. If you have the book, see whether you can figure it out yourself first.
[Note: this is a hard task. These two problems do not look alike superficially and, though, they touch on a general principle, they dont use that principle in the same way. Challenge yourself. :) ]
For those of you who are DS geeks, problem 218 in the quant review is an example of a relatively rare phenomenon: a Yes/No problem in which the answer is actually a definitive No rather than a definitive Yes. (Sorry. Had to geek out for a moment. If youre wondering why I told you that, ignore me. Carry on!)
Dont stop now: tell me more!
Of course! Join us next time, when Ill dive into a discussion of various interesting quant problems that I mentioned in this first installment. If you get the books yourself before then, see whether you can figure anything out about the problems I referenced.
Happy studying!