Insights from the 2021 GMAT Official Guide Books

I’ve reviewed the 2021 GMAT Official Guide, GMAT Quantitative Review and GMAT Verbal Review, comparing them to the 2020 editions. Every year, I look for new patterns and trends in the problems that have been added and removed. This year, key insights include:

1.     Many Problems Added, But Only the Diagnostic and One CR Removed. In all, there are 1,895 problems, including some problems only available online from the publisher Wiley. In the main Official Guide, there are 998 problems, including 32 new Problem Solving (PS), 10 new Data Sufficiency (DS), 19 new Critical Reasoning (CR), 31 new Sentence Correction (SC), and no new Reading Comprehension (RC). In the Quantitative Review, there are 373 problems, including 36 new PS and 18 new DS. In the Verbal Review, there are 348 problems, including 11 new RC, 23 new CR and 2 new SC. Only one CR problem that was in OG2020 was removed from OG2021; it was an assumption problem (OG2020 CR692).

Perhaps most important for those purchasing the 2021 books, the 100 quant and verbal diagnostic problems that have been part of the OG for many years are now only accessible through Wiley online – after purchasing the book(s), set up an online account at www.wiley.com/go/officialgmatbook and look for the “Online Exclusive” problems. With a few exceptions, these 100 problems are great, classic GMAT problems. Most people find that some are very easy, and some are quite hard.

2.     Profit & Gross Profit. Four new problems have been added to the existing handful of problems that involve profit or gross profit. These are concepts GMAT test takers must understand. See OG2021 PS117 and DS488 as well as QR2021 DS273 and DS277.

3.     Comparisons in Statistics. Many new problems relate to the interplay between different statistics – for example, mean vs. range (OG2021 DS274; QR2021 DS221, DS224, DS248, DS265) and standard deviation vs. range (QR2021 DS249).

4.     Quant Problems Requiring Detail Work. For these new problems, organizing information quickly on a noteboard/whiteboard is key to an efficient analysis. For example, see QR2021 PS204 and PS 207.

5.     Challenging New Quant Problems in QR2021. The most difficult new quant problems appear in the QR2021 book. See PS179, PS204, PS205, PS207, PS208, PS209, PS210 and PS212.

6.     Emphasis on Primary Purpose Problems in RC. There are very few new RC problems: the main Official Guide has none, and the Verbal Review only has 11. In an unusual move, the GMAC added primary purpose problems to three existing passages in the Verbal Review, underscoring the importance of mastering primary purpose strategies.

7.     Math Error in the Intro to Critical Reasoning. In paragraph 1 of section 5 in chapter 7.3, the statement, “All primes are odd numbers” is identified as a correct premise. Since the number 2 is prime, this statement is, of course, an incorrect premise. Sometimes the verbal experts don’t know the quant material, and vice versa!

8.     New CR Problems Focusing on the Use / Misuse of Data. When CR problems involve concepts such as averages, percents or ratios, the reasoning will often center on the use or rather misuse of data. See OG2021 CR682, CR707 and CR708.

9.     Challenging New CR Problems in VR2021. Many of the most difficult new CR problems appear in the VR2021 book. See CR198, CR199, CR200, CR201, CR208, CR228, CR229, CR231, CR232 and CR233.

10.  Many New SC Comparison Problems. Problems focusing on the logic and structure of comparisons are often among the trickiest SC problems. Several new problems offer good practice. See OG2021 SC827, SC839, SC868, SC869, SC871, SC880, SC888, SC914, SC916, SC920 and SC931.

11.  Many New SC Pronoun Problems. In particular, there are several new problems requiring an analysis of whether pronouns have clear referents. See OG2021 SC821, SC822, SC827, SC829, SC838, SC840, SC852, SC857, SC858, SC866, SC867, SC872 and SC880 as well as VR2021 SC268.

There are a few more key observations that I hold in reserve for Simply Brilliant's clients! My approach to GMAT prep includes assigning targeted lists of official problems, and these lists include many great problems in old Official Guides that have been removed in the newer editions. The old editions represent great resources for those looking for a larger supply of problems that were actually once on the real GMAT, and these books are generally available at Amazon.com.