{"id":19131,"date":"2020-12-02T19:08:22","date_gmt":"2020-12-02T19:08:22","guid":{"rendered":"https:\/\/www.manhattanprep.com\/gmat\/?p=19131"},"modified":"2020-12-22T17:55:26","modified_gmt":"2020-12-22T17:55:26","slug":"the-official-guide-2021","status":"publish","type":"post","link":"https:\/\/www.manhattanprep.com\/gmat\/blog\/the-official-guide-2021\/","title":{"rendered":"The Official Guide 2021 Review and Highlights"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-19138\" src=\"https:\/\/www.manhattanprep.com\/gmat\/wp-content\/uploads\/sites\/18\/2020\/09\/untitled-design-2.png\" alt=\"\" width=\"1920\" height=\"1006\" \/><\/p>\n<p><span style=\"font-weight: 400;\">GMAC published the 2021 edition of its Official Guide series in late June and we\u2019ve got all of the highlights for the main guide.<\/span><\/p>\n<p><!--more--><\/p>\n<h4><strong>Is it worth buying?<\/strong><\/h4>\n<p><span style=\"font-weight: 400;\">Definitely. I wouldn\u2019t study for the GMAT without using at least the main official guide (OG) book. There are four books in all:<\/span><\/p>\n<ol>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The GMAT Official Guide (aka, the main OG): Contains more than 1,000 problems across all three multiple-choice sections of the exam (Quant, Verbal, and Integrated Reasoning) as well as dozens of sample essay prompts.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The GMAT Official Guide Quantitative Review: Contains more than 350 Quant problems that do not appear in the main OG.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The GMAT Official Guide Verbal Review: Contains more than 350 Verbal problems that do not appear in the main OG.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">GMAT Official Advanced Questions: Contains 300 hard Quant and Verbal problems that do not appear in any of the other OGs.<\/span><\/li>\n<\/ol>\n<p><span style=\"font-weight: 400;\">The main OG contains so many problems that I find most students don\u2019t need the Quant and Verbal-only books, but they\u2019re available if you want more. If you\u2019re going for a 700+ kind of score, then you may also want the Advanced OG (but start with the main OG unless your score is already in the upper 600s).<\/span><\/p>\n<h4><strong>How is it different from the prior edition (Official Guide 2020)?<\/strong><\/h4>\n<p><span style=\"font-weight: 400;\">There are 92 new problems:<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">32 Problem Solving<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">10 Data Sufficiency<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">19 Critical Reasoning<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">31 Sentence Correction<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">There are no new Reading Comprehension passages or problems. In addition, one Critical Reasoning question was removed from the book, so the total number of CR problems increased by 18, not 19. No other problems were removed from the book.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">GMAC did remove the Diagnostic Test chapter, which contained 100 problems, but you still have access to all of these problems at their <\/span><a href=\"https:\/\/www.efficientlearning.com\/gmat\/\"><span style=\"font-weight: 400;\">Efficient Learning<\/span><\/a><span style=\"font-weight: 400;\"> online platform (you get access to this platform for 1 year with your purchase of the book). You\u2019ll find the 100 Diagnostic problems in the \u201cOnline Exclusive\u201d problem bank, and you\u2019ll have access to a number of Integrated Reasoning practice problems that are also available only online. And, as a bonus, the online platform contains all of the problems that are printed in the book; you can create problem sets (more on this below), practice time management, and track certain performance metrics.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">There\u2019s one interesting new feature this year: digital flash cards to help you study. I haven\u2019t tried them yet so can\u2019t tell you whether they\u2019re good, but I\u2019m a big fan of flash cards in general. They\u2019re great for anything you need to memorize\u2014facts, formulas, and what I call Know the Code takeaways. These takeaways come in the form \u201cWhen I see _____\u201d (on the front side of the flash card) and \u201cI\u2019ll think \/ do ______\u201d (on the back side of the flash card). For example: When I see a <\/span><i><span style=\"font-weight: 400;\">comma which<\/span><\/i><span style=\"font-weight: 400;\"> vs. <\/span><i><span style=\"font-weight: 400;\">comma \u2013ing<\/span><\/i><span style=\"font-weight: 400;\"> difference in the answers on an SC problem, I\u2019ll think \u201cmodifiers\u201d and figure out what the modifier is referring to.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">If you\u2019re debating between buying OG2020 and OG2021, I\u2019d go for 2021. You\u2019ll have all of the same problems that are in OG2020, plus 92 additional, brand-new problems as well as access to the new flash cards.<\/span><\/p>\n<h4><strong>How should I use the OG in my studies?<\/strong><\/h4>\n<p><span style=\"font-weight: 400;\">If you\u2019re using our study materials, we\u2019ve classified all of the OG problems by problem type and by chapter \/ content area from our books. Anyone can access these classification lists by creating a free <\/span><a href=\"https:\/\/www.manhattanprep.com\/gmat\/resources\/\"><span style=\"font-weight: 400;\">Atlas GMAT Starter Kit<\/span><\/a><span style=\"font-weight: 400;\"> account on our website. You\u2019ll find the OG problem lists under Official Guide Resources on the left-hand menu bar. (The Starter Kit has a bunch of other free resources as well, FYI.)<\/span><\/p>\n<p><span style=\"font-weight: 400;\">I would also take a look at this blog series on <\/span><a href=\"https:\/\/www.manhattanprep.com\/gmat\/blog\/practicing-sets-of-gmat-problems-mimic-the-real-test-part-1-of-3\/\"><span style=\"font-weight: 400;\">creating your own problem sets<\/span><\/a><span style=\"font-weight: 400;\">. You\u2019ll use the problems in different ways during different stages of your studies and that series explains what to do when.<\/span><\/p>\n<h4><strong>Are there any trends in the new problems?<\/strong><\/h4>\n<p><span style=\"font-weight: 400;\">There are a lot of really interesting new problems! I can\u2019t, unfortunately, show any of them to you (copyright law&#8230;), but I\u2019ll tell you what I think about some of them and you can look them up yourself in your own copy of the book.\u00a0<\/span><\/p>\n<h4><i><span style=\"font-weight: 400;\">Quant<\/span><\/i><\/h4>\n<p><span style=\"font-weight: 400;\">Overall, I noticed a ton of stories and a lot of opportunities to logic something out or to estimate. There are also some pure math problems, but there is a definite trend around the ability to think logically about math. (And I love that because it makes the test a lot easier to take\u2014once you train yourself to think logically about math. Bonus: That ability will help you in b-school and at work.)<\/span><\/p>\n<p><span style=\"font-weight: 400;\">There were also some beautiful traps\u2014the test writers really are masters at figuring out how to tempt us to go down the wrong path. (Seriously, I consider them artists in this way!)<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Here are a few of my favorite Problem Solving and Data Sufficiency problems that are new to OG 2021. When you have your copy, try the problems first and then read what I thought.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">PS #94<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary: <\/span><\/i><span style=\"font-weight: 400;\">Gives us kilometers per hour and asks for the answer in miles per hour (along with another calculation).<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it: <\/span><\/i><span style=\"font-weight: 400;\">The middle answer is the answer if you don\u2019t convert to miles (ie, it\u2019s a trap!). From there, you can eyeball to tell whether the answer should be greater or less than that trap value, so that gets you down to two answers. And you can use common Fraction Decimal Percent (FDP) conversions (0.625 = 5\/8) and estimation to get down to the single correct answer without too much trouble.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">PS #117<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary:<\/span><\/i><span style=\"font-weight: 400;\"> What I call a Wall of Text (WoT) problem. Complicated story with data for each month of an entire year\u2014and you do actually need to calculate profit for the whole 12 months.<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it:<\/span><\/i><span style=\"font-weight: 400;\"> You can balance groups of months and just find the aggregate difference. For example, for 3 months, you lose $32K per month and for 3 months you gain $36K per month. For each pair of win-loss months, then, you gain $4K, so total you gain $12K, which represents your profit for 6 months of the year. Keep going from there to get your answer.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">PS #259<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary:<\/span><\/i><span style=\"font-weight: 400;\"> This is the hardest of the new-to-2021 PS problems. It\u2019s a parallelogram, part of which is split into a triangle and they want to know what fraction the triangle represents of the <\/span><span style=\"font-weight: 400;\">rest<\/span><span style=\"font-weight: 400;\"> of the parallelogram (not the whole thing).<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it:<\/span><\/i><span style=\"font-weight: 400;\"> The diagram is drawn to scale, so you know immediately that (A) can\u2019t be correct (too big) and (E) is almost certainly too small. Down to three answers in like 5 seconds. Next, eyeball the triangle as a fraction of the <\/span><i><span style=\"font-weight: 400;\">whole<\/span><\/i><span style=\"font-weight: 400;\"> parallelogram. That\u2019s about 1\/4&#8230;but that\u2019s not what they asked. And, hey, that value is in the answers, so cross it off. There are only two answers left, one greater than 1\/4 and one less than 1\/4. Logic it out: If the triangle as a fraction of the <\/span><i><span style=\"font-weight: 400;\">whole<\/span><\/i><span style=\"font-weight: 400;\"> parallelogram is 1\/4, then the triangle has to be a greater fraction of just <\/span><i><span style=\"font-weight: 400;\">part<\/span><\/i><span style=\"font-weight: 400;\"> of the parallelogram, since part of the parallelogram is smaller than the whole parallelogram. Done.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">DS #488: This is my favorite one of them all! This looks like an easier problem but it\u2019s one of the highest-numbered in the chapter&#8230;and for good reason.<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary:<\/span><\/i><span style=\"font-weight: 400;\"> Another WoT (wall of text) problem but the question seems really easy: What\u2019s the discounted price of the second shirt?<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it:<\/span><\/i><span style=\"font-weight: 400;\"> Take your time on understanding the story. If you spot what this thing is <\/span><i><span style=\"font-weight: 400;\">really<\/span><\/i><span style=\"font-weight: 400;\"> asking, the solution is straightforward. If you don\u2019t, you\u2019ll almost certainly fall into a trap. The discounted price of the second shirt is <\/span><i><span style=\"font-weight: 400;\">the same as<\/span><\/i><span style=\"font-weight: 400;\"> the cost to manufacture the shirt. The story literally describes selling the shirt at cost! One of the two statements gives you the manufacturing cost outright and the other statement is useless by itself\u2014once you know that you\u2019re looking for the manufacturing cost.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4><i><span style=\"font-weight: 400;\">Verbal<\/span><\/i><\/h4>\n<p><span style=\"font-weight: 400;\">In the Critical Reasoning chapter, 11 of the 19 new problems were Strengthen or Weaken. These two types are quite frequent on the real test. My favorite of the new problems is a Weaken (details below).<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Each Sentence Correction problem tests multiple grammar rules, as always. I noticed a lot of sentence structure issues, parallelism and comparisons, and some really interesting issues around meaning.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Here are a few of my favorite new problems. When you have your copy, try the problems first and then read what I thought.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">CR #707<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\"><!--more-->\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary: <\/span><\/i><span style=\"font-weight: 400;\">Some people want to limit the amount of homework assigned to kids under the age of 12. But the average homework time for students of this age is only about 30 minutes per night, so the argument\u2019s author disagrees and doesn\u2019t think it\u2019s necessary to limit homework. The question asks us to weaken the author\u2019s conclusion.<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it: <\/span><\/i><span style=\"font-weight: 400;\">The correct answer is so hard to spot! You actually have to bring in an understanding of statistics, so this is a great amalgamation of verbal and math skills. We accept as true the author\u2019s statement that the <\/span><i><span style=\"font-weight: 400;\">average<\/span><\/i><span style=\"font-weight: 400;\"> homework time for this group is ~30 minutes. But could it still be the case that <\/span><i><span style=\"font-weight: 400;\">some<\/span><\/i><span style=\"font-weight: 400;\"> percentage of these students have hours of homework a night, even though the average for <\/span><i><span style=\"font-weight: 400;\">all<\/span><\/i><span style=\"font-weight: 400;\"> students is only 30 minutes? Yes\u2014if other students in this group have almost no homework at all, so that the average still comes out to ~30 minutes. And that\u2019s what the correct answer establishes: that a lot of these students have very little homework (so a small subset of the total would have quite a bit of homework).<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">SC #854<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary: <\/span><\/i><span style=\"font-weight: 400;\">The sentence structure of the original sentence is similar to this: \u201cAlthough cats, sleeping all day in the heat of summer, by nighttime they begin to prowl around in the dark, hunting for prey.\u201d The actual sentence is of course longer and more complicated, so it hides the fact that the opening <\/span><i><span style=\"font-weight: 400;\">Although<\/span><\/i><span style=\"font-weight: 400;\"> clause has no verb.<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it: <\/span><\/i><span style=\"font-weight: 400;\">This is a great introduction to overall sentence structure issues\u2014all four wrong answers create \u201cillegal\u201d sentence structures and can be eliminated for that reason. It\u2019s a great lesson in how to look at the overall sentence structure (vs. zeroing in on one specific \/ tiny \/ nitpicky grammar issue).<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">SC #867<\/span><\/p>\n<ul>\n<li style=\"list-style-type: none;\">\n<ul>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Summary:<\/span><\/i><span style=\"font-weight: 400;\"> The sentence structure of the original sentence is similar to this: \u201cAlthough when a cat grooms itself, it can cough up a small hairball, it will not choke the cat, (ignoring the rest of the original sentence because it doesn\u2019t matter for my example).\u201d The first pronoun <\/span><i><span style=\"font-weight: 400;\">it<\/span><\/i><span style=\"font-weight: 400;\"> refers to the cat but the second pronoun <\/span><i><span style=\"font-weight: 400;\">it<\/span><\/i><span style=\"font-weight: 400;\"> refers to the hairball. Because you\u2019re already primed to think that <\/span><i><span style=\"font-weight: 400;\">it<\/span><\/i><span style=\"font-weight: 400;\"> = <\/span><i><span style=\"font-weight: 400;\">cat<\/span><\/i><span style=\"font-weight: 400;\"> after the first instance, it\u2019s confusing when you get to the second <\/span><i><span style=\"font-weight: 400;\">it<\/span><\/i><span style=\"font-weight: 400;\">. The cat will not choke the cat?<\/span><\/li>\n<li style=\"font-weight: 400;\"><i><span style=\"font-weight: 400;\">Why I like it: <\/span><\/i><span style=\"font-weight: 400;\">In the notes I took just after I tried this one for the first time, the first thing I wrote was \u201cClever.\u201d I had to read the opening part of the sentence twice to understand what it was actually trying to say. What <\/span><i><span style=\"font-weight: 400;\">expands several hundred times<\/span><\/i><span style=\"font-weight: 400;\">? Presumably not the fish (imagine a trout expanding to the size of a whale&#8230;not going to happen!), so it must be the slime. (And the later, non-underlined portion of the sentence confirms this interpretation\u2014but I hadn\u2019t gotten there yet.) The fact that I couldn\u2019t initially understand the meaning actually indicates the problem with this sentence: It\u2019s ambiguous. The correct answer needs to be a lot more clear.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h4><strong>Anything else?<\/strong><\/h4>\n<p><span style=\"font-weight: 400;\">That\u2019s it! But I will repeat what I said at the beginning. Don\u2019t consider studying for the GMAT without getting yourself a copy of the OG. If you already have a copy of the 2020 edition, it\u2019s not necessary to purchase the new edition. But if you don\u2019t yet have a copy, I\u2019d recommend getting OG 2021.<\/span><\/p>\n<p><span style=\"font-weight: 400;\">Good luck and happy studying!\u00a0<\/span><\/p>\n<hr \/>\n<p><a id=\"bloglink\" href=\"https:\/\/www.manhattanprep.com\/instructors\/stacey-koprince\/\" target=\"_blank\" rel=\"noopener noreferrer\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-9719 size-thumbnail\" src=\"https:\/\/cdn2.manhattanprep.com\/gmat\/wp-content\/uploads\/sites\/18\/2015\/06\/stacey-koprince-150x150.png\" alt=\"stacey-koprince\" width=\"150\" height=\"150\" \/><\/a><em><strong><a href=\"https:\/\/www.manhattanprep.com\/instructors\/stacey-koprince\/?utm_source=manhattanprep.com%2Fgmat%2Fblog&#038;utm_medium=blog&#038;utm_content=KoprinceBioLinkGMATBlog&#038;utm_campaign=GMAT%20Blog\" target=\"_blank\" rel=\"noopener noreferrer\">Stacey Koprince<\/a> is a Manhattan Prep instructor based in Montreal, Canada and Los Angeles, California.\u00a0Stacey has been teaching the GMAT, GRE, and LSAT \u00a0for more than 15 years and is one of the most well-known instructors in the industry. Stacey loves to teach and is absolutely fascinated by standardized tests.\u00a0<a href=\"https:\/\/www.manhattanprep.com\/gmat\/classes\/?utm_source=manhattanprep.com%2Fgmat%2Fblog&#038;utm_medium=blog&#038;utm_content=KoprinceCoursesLinkGMATBlog&#038;utm_campaign=GMAT%20Blog#instructor\/86\">Check out Stacey\u2019s upcoming GMAT courses here<\/a>.<\/strong><\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>GMAC published the 2021 edition of its Official Guide series in late June and we\u2019ve got all of the highlights for the main guide.<\/p>\n","protected":false},"author":6,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[873,929,874,930,2,52877,52945,8,1,10],"tags":[289,58349,561,566,58350],"yst_prominent_words":[54040,58347,58339,54401,54398,58343,54127,55209,53704,53787,58344,53674,54407,58340,58345,58338,58348,58341,58342,58346],"class_list":["post-19131","post","type-post","status-publish","format-standard","hentry","category-for-current-studiers","category-gmat-prep","category-gmat-resources","category-gmat-study-guide","category-how-to-study","category-in-the-news","category-products-and-services","category-quant-on-gmat","category-uncategorized","category-verbal-on-gmat","tag-gmat-official-guide","tag-gmat-official-guide-2021-edition","tag-official-guide","tag-og","tag-og2021"],"_links":{"self":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/19131","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/comments?post=19131"}],"version-history":[{"count":10,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/19131\/revisions"}],"predecessor-version":[{"id":19145,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/posts\/19131\/revisions\/19145"}],"wp:attachment":[{"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/media?parent=19131"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/categories?post=19131"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/tags?post=19131"},{"taxonomy":"yst_prominent_words","embeddable":true,"href":"https:\/\/www.manhattanprep.com\/gmat\/wp-json\/wp\/v2\/yst_prominent_words?post=19131"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}