Preview of 2016 GMAT Official Guide Math

2016 GMAT Official GuideIn this third post of this series of exclusive previews of the 2016 GMAT Official Guides, we now turn to the math section of the main Official Guide. We will focus on how the 2016 GMAT Official Guide differs from the 2015 edition in terms of math question difficulty and math concepts.

Problem Solving – Difficulty

Both the 2015 and 2016 editions of the GMAT Official Guide contain 230 Problem Solving questions, excluding the identical 24 Problem Solving questions in the Diagnostic Exam portion of the guides. But the allocation of question difficulty, as assigned by the GMAC, has noticeably shifted. In particular, the Easy and Hard categories have expanded whereas the Medium category has shrunk considerably. A big portion of these change resulted from the GMAC upgrading 36 questions from Medium difficulty (in the 2015 edition) to Hard (in the 2016 edition).

Difficulty 2016 2015 Change
Easy 55 37 +18
Medium 52 93 (41)
Hard 123 100 +23
Total 230 230

A total of 57 brand new Problem Solving questions, which we have never seen before, appear in the 2016 GMAT Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 21 / 24 / 12. This is in lieu of 57 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 12 / 20 / 25. Let’s further break down how each of these difficulty categories has changed.

Easy Problem Solving

Additions:
21 new questions
9 downgraded from Medium

Subtractions:
12 questions removed

Net change: +18 questions

Medium Problem Solving

Additions:
24 new questions

Subtractions:
20 questions removed
9 downgraded to Easy
36 upgraded to Hard

Net change: -41 questions

Hard Problem Solving

Additions:
12 new questions
36 upgraded from Medium

Subtractions:
25 questions removed

Net change: +23 questions

Problem Solving – Concepts

Let’s now consider changes in the concepts of the 57 new (in 2016) and the 57 removed (from 2015) Problem Solving questions. GMAT Genius classifies questions based on their primary and secondary concepts. In order to observe trends, we have condensed our categorization as follows:

Type Concept 2016 2015 Change
Arithmetic Basic 3 5 (2)
Arithmetic Absolute Value 0 1 (1)
Arithmetic Divisibility & Factors 2 3 (1)
Arithmetic Exponents & Roots 4 3 1
Arithmetic Fractions & Ratios 3 5 (2)
Arithmetic Percents 4 2 2
Arithmetic Positive/Negative 1 1
Algebra Formulas 2 0 2
Algebra Inequalities 1 4 (3)
Algebra Linear Equations 2 3 (1)
Algebra Quadratics 2 2
Algebra Simultaneous Equations 2 5 (3)
Geometry Various 15 14 1
Statistics Averages 5 1 4
Statistics Other 1 1
Word Problems Functions & Sequences 2 0 2
Word Problems Other Various 8 7 1

Although we cannot draw definite conclusions from this data about question composition on the GMAT, what stands out is the decrease in algebraic inequalities and simultaneous equations, the decrease in arithmetic fundamentals, and the increase in averages.

Data Sufficiency – Difficulty

Both the 2015 and 2016 editions of the GMAT Official Guide contain 174 Data Sufficiency questions, excluding the identical 24 Data Sufficiency questions in the Diagnostic Exam portion of the guides. As with Problem Solving, the allocation of question difficulty has noticeably shifted. Once again, the Easy and Hard categories have expanded whereas the Medium category has shrunk considerably. A big portion of these change resulted from the GMAC upgrading 24 questions from Medium difficulty (in the 2015 edition) to Hard (in the 2016 edition).

Difficulty 2016 2015 Change
Easy 38 24 +14
Medium 34 64 (30)
Hard 102 86 +16
Total 174 174

A total of 44 brand new Data Sufficiency questions, which we have never seen before, appear in the 2016 GMAT Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 17 / 12 / 15. This is in lieu of 44 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 10 / 11 / 23. Let’s further break down how each of these difficulty categories has changed.

Easy Data Sufficiency

Additions:
17 new questions
7 downgraded from Medium

Subtractions:
10 questions removed

Net change: +14 questions

Medium Data Sufficiency

Additions:
12 new questions

Subtractions:
11 questions removed
7 downgraded to Easy
24 upgraded to Hard

Net change: -30 questions

Hard Data Sufficiency

Additions:
15 new questions
24 upgraded from Medium

Subtractions:
23 questions removed

Net change: +16 questions

Data Sufficiency – Concepts

Let’s now consider changes in the concepts of the 44 new (in 2016) and the 44 removed (from 2015) Data Sufficiency questions. GMAT Genius classifies questions based on their primary and secondary concepts. In order to observe trends, we have condensed our categorization as follows:

Type Concept 2016 2015 Change
Arithmetic Basic 0 4 (4)
Arithmetic Absolute Value 0 1 (1)
Arithmetic Exponents 4 2 2
Arithmetic Fractions & Ratios 1 3 (2)
Arithmetic Percents 6 2 4
Arithmetic Positive/Negative 2 1 1
Algebra Simultaneous Equations 1 8 (7)
Algebra Other 7 5 2
Geometry Coordinate 3 1 2
Geometry Other 6 5 1
Statistics Averages 2 3 (1)
Statistics Other 2 0 2
Word Problems Various 10 9 1

Although we again cannot draw definite conclusions from this data about question composition on the GMAT, what clearly stands out is the decrease in algebraic simultaneous equations and basic arithmetic concepts, offset by an increase in percents.

Removed Questions

Here is the list of the math questions that have been removed from the 2015 edition of the GMAT Official Guide. We’ll publish a list of the new math questions in the 2016 GMAT Official Guide after it publicly releases.

Problem Solving – 57 questions removed:

1, 2, 3, 5, 6, 23, 24, 28, 29, 32, 33, 35, 38, 39, 40, 43, 45, 47, 48, 50, 53, 62, 73, 78, 86, 90, 96, 103, 104, 111, 113, 121, 147, 152, 153, 159, 161, 165, 167, 171, 173, 175, 176, 179, 184, 187, 191, 192, 195, 197, 201, 202, 205, 220, 221, 225, 227

Data Sufficiency – 44 questions removed:

1, 2, 3, 6, 8, 13, 16, 17, 19, 20, 30, 36, 43, 45, 50, 56, 61, 72, 86, 87, 88, 89, 104, 106, 107, 112, 115, 121, 132, 136, 138, 140, 145, 148, 151, 153, 155, 156, 158, 160, 161, 162, 165, 174

Key Takeaways

Keep in mind that we cannot draw firm conclusions about the GMAC’s intent in making changes to the question composition in the 2016 GMAT Official Guide. That said, we can observe certain trends and speculate on what those changes may imply.

Between Problem Solving and Data Sufficiency, the GMAC has upgraded 60 questions from Medium difficulty to Hard. We can only presume that the GMAC is moving away from the trend of recent years of increasing the difficulty of the math section. If correct, this would bring welcome relief to many future GMAT hopefuls.

The changes in concepts as discussed above seem consistent with what we’ve observed in the 2016 Quantitative Official Guide. Simultaneous equations, in particular, have been reduced significantly. The GMAC really seems to be moving towards math questions that require more analytical reasoning to solve rather than rote usage of formulas and fundamental math techniques.

We’re still working our way through the Verbal sections of the 2016 GMAT Official Guide, and will post our analysis as soon as we can. Stay tuned!

Preview of 2016 GMAT Verbal Official Guide

2016 GMAT Verbal Official GuideI have been working closely with the publisher of the Official Guide for GMAT Review over the past few weeks, in advance of the June 8 release of the 2016 editions, to help improve the online version of the Official Guides. As with my prior post on the Quantitative Guide, I want to give you an overview of how the 2016 GMAT Verbal Official Guide differs from the 2015 edition in terms of question difficulty and concepts.

Sentence Correction – Difficulty

Both the 2015 and 2016 editions of the GMAT Verbal Official Guide contain 113 Sentence Correction questions. But the allocation of question difficulty, as assigned by the GMAC, has noticeably shifted. In particular, the Easy and Medium categories have expanded whereas the Hard category has shrunk. A big portion of these change resulted from the GMAC downgrading 12 questions from Hard difficulty (in the 2015 edition) to Medium (in the 2016 edition). Interestingly, two Hard questions (#70 and #111 in the 2015 edition) have also been downgraded all the way to Easy.

Difficulty 2016 2015 Change
Easy 31 26 +5
Medium 51 38 +13
Hard 31 49 (18)
Total 113 113

A total of 25 brand new questions, which we have never seen before, appear in the 2016 GMAT Verbal Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 9 / 13 / 3. This is in lieu of 25 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 6 / 12 / 7. Let’s further break down how each of these difficulty categories has changed.

Easy Sentence Correction

Additions:
9 new questions
1 downgraded from Medium
2 downgraded from Hard

Subtractions:
6 questions removed
1 upgraded to Medium

Net change: +5 questions

Medium Sentence Correction

Additions:
13 new questions
1 upgraded from Easy
12 downgraded from Hard

Subtractions:
12 questions removed
1 downgraded to Easy

Net change: +13 questions

Hard Sentence Correction

Additions:
3 new questions

Subtractions:
7 questions removed
2 downgraded to Easy
12 downgraded to Medium

Net change: -18 questions

Sentence Correction – Concepts

Let’s now consider changes in the concepts of the 25 new (in 2016) and the 25 removed (from 2015) Sentence Correction questions. We have categorized these questions based on the primary grammar concepts that are tested on Sentence Correction.

Concept 2016 2015 Change
Verb Agreement 1 3 (2)
Verb Tense 4 5 (1)
Pronoun Ambiguity 0 1 (1)
Pronoun Agreement 2 2
Parallel Construction 8 9 (1)
Misplaced Modifiers 2 0 2
Idioms 2 1 1
Comparison & Quantity 2 1 1
Expression & Meaning 4 3 1

Although we cannot draw definite conclusions from this data about question composition on the GMAT, we are surprised by the decrease in verb-related questions.

Critical Reasoning – Difficulty

Both the 2015 and 2016 editions of the GMAT Verbal Official Guide contain 83 Critical Reasoning questions. The allocation of question difficulty has noticeably shifted away from Medium. A whopping 21 questions (more than 25%) have been assigned a different difficulty level, including four Hard questions (#64, #72, #79, #80 in the 2015 edition) that have been downgraded all the way to Easy.

Difficulty 2016 2015 Change
Easy 34 25 +9
Medium 26 38 (12)
Hard 23 20 +3
Total 83 83

A total of 25 brand new questions, which we have never seen before, appear in the 2016 GMAT Verbal Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 7 / 9 / 9. This is in lieu of 25 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 6 / 14 / 5. Let’s further break down how each of these difficulty categories has changed.

Easy Critical Reasoning

Additions:
7 new questions
7 downgraded from Medium
4 downgraded from Hard

Subtractions:
6 question removed
3 upgraded to Medium

Net change: +9 questions

Medium Critical Reasoning

Additions:
9 new questions
3 upgraded from Easy
2 downgraded from Hard

Subtractions:
14 questions removed
7 downgraded to Easy
5 upgraded to Hard

Net change: -12 questions

Hard Critical Reasoning

Additions:
9 new questions
5 upgraded from Medium

Subtractions:
5 questions removed
4 downgraded to Easy
2 downgraded to Medium

Net change: +3 questions

Critical Reasoning – Concepts

Let’s now consider changes in the concepts of the 25 new (in 2016) and the 25 removed (from 2015) Critical Reasoning questions. We have grouped these questions based on the question type categorization that GMAT Genius uses for Critical Reasoning.

Concept 2016 2015 Change
Weaken 6 8 (2)
Strengthen 4 3 1
Assumption 1 3 (2)
Reasoning 1 0 1
Conclusion 1 2 (1)
Explain 3 3
Evaluate 2 4 (2)
Boldface 2 1 1
Complete the Passage 5 1 4

Although we cannot draw definite conclusions from this data about question composition on the GMAT, what clearly stands out is the increase in the Complete the Passage category.

Reading Comprehension – Difficulty

The 2016 edition of the GMAT Verbal Official Guide contains 105 Reading Comprehension questions, one more than in the 2015 edition. The allocation of question difficulty has noticeably shifted from Medium to Easy. Surprisingly, 35 questions (over 30%) have swapped difficulty from Medium to Hard or vice versa.

Difficulty 2016 2015 Change
Easy 26 17 +9
Medium 47 55 (8)
Hard 32 32
Total 105 104 +1

A total of 26 brand new questions, which we have never seen before, appear in the 2016 GMAT Verbal Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 15 / 4 / 7. These 26 questions are in 5 new passages with difficulty ratings of Easy / Medium / Hard as follows: 3 / 1 / 1.

A total of 25 questions have been removed from the 2015 edition, with difficulty ratings of Easy / Medium / Hard as follows: 6 / 11 / 8. This represents 4 passages with difficulty ratings of Easy / Medium / Hard as follows: 1 / 2 / 1. Let’s further break down how each of these difficulty categories has changed.

Easy Reading Comprehension

Additions:
15 new questions

Subtractions:
6 question removed

Net change: +9 questions

Medium Reading Comprehension

Additions:
4 new questions
17 downgraded from Hard

Subtractions:
11 questions removed
18 upgraded to Hard

Net change: -8 questions

Hard Reading Comprehension

Additions:
7 new questions
18 upgraded from Medium

Subtractions:
8 questions removed
17 downgraded to Medium

Net change:

Reading Comprehension – Concepts

Let’s now consider changes in the concepts of the 26 new (in 2016) and the 25 removed (from 2015) Reading Comprehension questions. We have grouped these questions based on the question type categorization that GMAT Genius uses for Reading Comprehension.

Concept 2016 2015 Change
Primary Purpose 3 2 1
Author’s Tone 0 1 (1)
Organization 1 3 (2)
Function 3 1 2
Specific Reference 9 10 (1)
Inference 10 5 5
Critical Reasoning 0 3 (3)

Although we cannot draw definite conclusions from this data about question composition on the GMAT, what clearly stands out is the increase in the Inference category and the decrease in the Critical Reasoning category.

Removed Questions

Here is the list of the questions that have been removed from the 2015 edition of the GMAT Verbal Official Guide. We’ll publish a list of the new questions in the 2016 GMAT Verbal Official Guide after it publicly releases.

Sentence Correction – 25 questions removed:

3, 6, 7, 8, 20, 21, 27, 34, 35, 36, 38, 39, 40, 41, 47, 51, 61, 62, 72, 76, 81, 93, 99, 101, 112

Critical Reasoning – 25 questions removed:

4, 7, 16, 21, 22, 23, 26, 27, 30, 36, 37, 40, 42, 44, 46, 48, 53, 58, 60, 62, 66, 69, 71, 73, 75

Reading Comprehension – 25 questions removed:

12 to 17, 33 to 38, 56 to 60, 77 to 84

Key Takeaways

We cannot draw firm conclusions about the GMAC’s intent in making changes to the question composition in the 2016 GMAT Verbal Official Guide. That said, we can observe certain trends and speculate on what those changes may imply.

By downgrading 14 Hard Sentence Correction questions without upgrading any questions to Hard, the GMAC seems to imply a greater rigor within Sentence Correction. The big shifts in question difficulty within Critical Reasoning and Reading Comprehension seem to imply that the GMAC is more closely assessing Verbal question difficulty than perhaps it did previously.

The changes in Sentence Correction concepts are not significant enough for us to reach any conclusions. The increases in the Complete the Passage category for Critical Reasoning and in the Inference category for Reading Comprehension seem to indicate that the GMAC is placing greater emphasis on analytical reasoning skills to solve CR and RC questions.

Look for more detailed analysis and critique of the 2016 GMAT Official Guides in the coming weeks from GMAT Genius.

Sneak Preview of 2016 GMAT Quantitative Official Guide

2016 GMAT Quantitative Official GuideI have been working closely with the publisher of the Official Guide for GMAT Review over the past few weeks, in advance of the June 8 release of the 2016 editions, to help improve the online version of the Official Guides. In doing so, I have thoroughly analyzed the 2016 versions of the GMAT Official Guides, and want to give you an overview of what to expect. Out of respect for the GMAC, I cannot share specific questions. In this post, we will instead focus specifically on how the 2016 GMAT Quantitative Official Guide differs from the 2015 edition in terms of question difficulty and math concepts.

Problem Solving – Difficulty

Both the 2015 and 2016 editions of the GMAT Quantitative Official Guide contain 176 Problem Solving questions. But the allocation of question difficulty, as assigned by the GMAC, has noticeably shifted. In particular, the Easy category has expanded whereas the Medium category has shrunk. A big portion of these change resulted from the GMAC downgrading 10 questions from Medium difficulty (in the 2015 edition) to Easy (in the 2016 edition). Interestingly, one Hard question (#159 in the 2015 edition) has also been downgraded all the way to Easy.

Difficulty 2016 2015 Change
Easy 82 67 +15
Medium 57 74 (17)
Hard 37 35 +2
Total 176 176

A total of 44 brand new questions, which we have never seen before, appear in the 2016 GMAT Quantitative Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 22 / 13 / 9. This is in lieu of 44 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 17 / 20 / 7. Let’s further break down how each of these difficulty categories has changed.

Easy Problem Solving

Additions:
22 new questions
10 downgraded from Medium
1 downgraded from Hard

Subtractions:
17 questions removed
1 upgraded to Medium

Net change: +15 questions

Medium Problem Solving

Additions:
13 new questions
1 upgraded from Easy

Subtractions:
20 questions removed
10 downgraded to Easy
1 upgraded to Hard

Net change: -17 questions

Hard Problem Solving

Additions:
9 new questions
1 upgraded from Medium

Subtractions:
7 questions removed
1 downgraded to Easy

Net change: +2 questions

Problem Solving – Concepts

Let’s now consider changes in the concepts of the 44 new (in 2016) and the 44 removed (from 2015) Problem Solving questions. GMAT Genius classifies questions based on their primary and secondary concepts. In order to observe trends, we have condensed our categorization as follows:

Type Concept 2016 2015 Change
Arithmetic Basic 2 2
Arithmetic Absolute Value 2 0 2
Arithmetic Divisibility 1 1
Arithmetic Exponents 3 4 (1)
Arithmetic Fractions & Ratios 4 2 2
Arithmetic Percents 3 5 (2)
Arithmetic Positive/Negative 1 1
Algebra Formulas 2 0 2
Algebra Inequalities 2 2
Algebra Linear Equations 2 4 (2)
Algebra Quadratics 1 1
Algebra Simultaneous Equations 2 4 (2)
Geometry Coordinate 1 1
Geometry Other 4 4
Statistics Averages 2 4 (2)
Statistics Other 0 1 (1)
Word Problems Combinatorics 2 1 1
Word Problems Functions & Sequences 5 1 4
Word Problems Groups (Sets) 1 1
Word Problems Interest 1 0 1
Word Problems Revenue & Profit 1 2 (1)
Word Problems Rate & Work 2 3 (1)

Although we cannot draw definite conclusions from this data about question composition on the GMAT, what clearly stands out is the decrease in algebraic equations and the increase in functions and sequences.

Data Sufficiency – Difficulty

Both the 2015 and 2016 editions of the GMAT Quantitative Official Guide contain 124 Data Sufficiency questions. As with Problem Solving, the allocation of question difficulty has noticeably shifted. Once again, the Easy category has expanded whereas the Medium category has shrunk. Interestingly, the GMAC has upgraded 23 Medium questions (from the 2015 edition) to Hard.

Difficulty 2016 2015 Change
Easy 22 9 +13
Medium 25 42 (17)
Hard 77 73 +4
Total 124 124

A total of 31 brand new questions, which we have never seen before, appear in the 2016 GMAT Quantitative Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 14 / 11 / 6. This is in lieu of 31 questions from the 2015 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 1 / 6 / 24. Let’s further break down how each of these difficulty categories has changed.

Easy Data Sufficiency

Additions:
14 new questions
1 downgraded from Medium

Subtractions:
1 question removed
1 upgraded to Medium

Net change: +13 questions

Medium Data Sufficiency

Additions:
11 new questions
1 downgraded from Hard
1 upgraded from Easy

Subtractions:
6 questions removed
1 downgraded to Easy
23 upgraded to Hard

Net change: -17 questions

Hard Data Sufficiency

Additions:
6 new questions
23 upgraded from Medium

Subtractions:
24 questions removed
1 downgraded to Medium

Net change: +4 questions

Data Sufficiency – Concepts

Let’s now consider changes in the concepts of the 31 new (in 2016) and the 31 removed (from 2015) Data Sufficiency questions. GMAT Genius classifies questions based on their primary and secondary concepts. In order to observe trends, we have condensed our categorization as follows:

Type Concept 2016 2015 Change
Arithmetic Basic 2 2
Arithmetic Absolute Value 1 0 1
Arithmetic Divisibility 0 3 (3)
Arithmetic Exponents 2 2
Arithmetic Fractions & Ratios 2 2
Arithmetic Percents 0 1 (1)
Arithmetic Positive/Negative 3 2 1
Algebra Inequalities 3 2 1
Algebra Linear Equations 0 3 (3)
Algebra Simultaneous Equations 3 6 (3)
Geometry Coordinate 3 0 3
Geometry Other 3 4 (1)
Statistics Averages 2 2 0
Statistics Other 2 0 2
Word Problems Functions & Sequences 1 0 1
Word Problems Probability 1 0 1
Word Problems Revenue & Profit 1 0 1
Word Problems Rate & Work 2 2 0

Although we again cannot draw definite conclusions from this data about question composition on the GMAT, what clearly stands out is the decrease in algebraic equations and divisibility concepts, offset by the increase in coordinate geometry and applied word problems.

Removed Questions

Here is the list of the questions that have been removed from the 2015 edition of the GMAT Quantitative Official Guide. We’ll publish a list of the new questions in the 2016 GMAT Quantitative Official Guide after it publicly releases.

Problem Solving – 44 questions removed:

4, 10, 11, 12, 14, 15, 16, 17, 18, 23, 25, 28, 30, 32, 37, 43, 45, 74, 75, 77, 84, 92, 99, 104, 106, 109, 111, 115, 120, 122, 123, 128, 132, 134, 138, 139, 141, 143, 144, 163, 165, 166, 167, 174

Data Sufficiency – 31 questions removed:

3, 23, 27, 28, 30, 36, 47, 56, 57, 60, 64, 68, 71, 72, 77, 84, 86, 92, 94, 97, 98, 103, 105, 108, 109, 110, 112, 114, 119, 120, 123

Key Takeaways

Keep in mind that we cannot draw firm conclusions about the GMAC’s intent in making changes to the question composition in the 2016 GMAT Quantitative Official Guide. That said, we can observe certain trends and speculate on what those changes may imply.

By downgrading 10 Medium Problem Solving questions to Easy while upgrading 23 Medium Data Sufficiency questions to Hard, the GMAC seems to be indicating that it considers Data Sufficiency more challenging than perhaps it did previously.

Furthermore, given the changes in concepts as discussed above, the GMAC seems to be moving away from questions that are more process-oriented (i.e. solve by following a set procedure) and towards applied questions that require more analytical reasoning to solve.

GMAT Genius will offer much more detailed analysis and critique of the 2016 GMAT Official Guides in the coming weeks. Stay tuned!

GMAT Official Guide 2015 Online Interface

GMAT Official Guides online accessFollowing up on our prior post about the new 2015 GMAT Official Guides, we now review the online study tools that accompany the printed books. Registration is quite easy. Once you register one book, you can select Profile to add the access codes for additional Official Guide books rather than starting the registration process anew. Your online account is valid for only six months. Due to this time limit, be sure to register only when you are ready to start preparing for the GMAT.

Online access includes three brief videos, one per book. The videos are in a Q&A format, with potential test takers asking and receiving answers to some questions about test preparation. Overall, these videos are not very insightful.

Online Interface

The primary purpose of the online account is not the videos, however, but the online question access. In our opinion, the online interface is poorly designed and detracts from the purpose of online question access.

Problem Set Options

You create a practice problem set by selecting any combination of question difficulty (Easy, Medium, or Hard) and question type (PS, DS, RC, CR, or SC), and the number of questions for the set. When choosing multiple question types, the types are all inter-mingled (i.e. they do not come in discrete blocks). Therefore, be sure to choose among either math question types or verbal types, but not both for a given practice set. You must also name your practice set; these names are listed in the review stage for your prior sessions. The system allows you to use the same name multiple times. But it will be helpful for you to create a unique, intuitive name for your future reference.

Finally, you must choose between Practice Mode (the default) and Exam Mode. In Practice Mode, you can view the answer / explanation for a question at any time. Similarly, you can review a summary table of all your responses so far for the current practice set. The time counter does not pause while you are viewing an answer, thereby defeating the purpose of time analytics. Also in Practice Mode, there is a button to take notes for each question. But this is a useless feature, because there is no way to ever access the notes that you took. We highly recommend that you use only Exam mode, in which you review your responses and explanations only after completing all questions in the practice set. Since the system keeps defaulting back to Practice Mode, be sure to switch to Exam Mode before starting a practice set.

Reading Comprehension

In either mode, Reading Comprehension presents only one question per passage. Even when practicing with only a limited set of RC questions, the passages are interspersed. For example, you may see a certain passage for questions 1, 5, and 8 in your set, with a different question each time for the same passage. Since it is not efficient or worthwhile to read the same passages over and over, the RC functionality is effectively useless. We recommend that you practice RC only in the physical book.

Progressing Through Problem Sets

Unlike the real exam, the test interface saves your answer as soon as you choose Next Question (in either mode). There is no Answer Confirm feature, so be sure that you have selected your final response before progressing. After you answer the last question in a practice set, you must select “View Test Results” in order to submit your answer. We found this to be non-intuitive.

As you progress through practice sets, the test does not give you repeat questions, unless you have already completed all the questions of that type at that difficulty level. You can bookmark questions and return to bookmarked questions in the review phase. Answer explanations are identical to those in the printed books. The test interface shows the time spent per question, but offers no performance analytics.

Poor Design Decisions

Questions are presented in a different order than in the book, and there is no way to easily cross-reference completed questions with the printed book. This makes it difficult to move back-and-forth between the book and online access. It would have been helpful, at a minimum, for each question to list the corresponding question number in the Official Guide. Even better, the interface could have presented a chart with the question numbers from the book, highlighting which questions have been completed online. Unfortunately such functionality is absent.

A calculator is available for all question types, even verbal. This reflects a poor design decision the part of GMAC and Wiley, since a calculator is not available on the real GMAT. Absolutely do not use the calculator – just pretend that it does not exist.

You can Pause and then Resume the test (in either mode). You can also choose End Test; the interface treats the remaining questions as unanswered. We encourage you to use these features sparingly, since they defeat the purpose of concentrated studying. The system logs out fairly quickly, after about 5 to 10 minutes of inactivity, so you may find yourself frequently having to log-back-in.

Diagnostic Test Mode

In addition to the Practice and Exam Modes, the main Official Guide also offers a Diagnostic Mode. This section presents the same questions, in the same order, that are in Chapter 3 (Diagnostic Test) of the Official Guide. You can select which question type(s) you wish to complete in one sitting. Since questions are presented sequentially, the Reading Comprehension section is fine in this mode.

Unlike the Practice and Exam modes, your results are not saved for the Diagnostic exam. Once you exit the review screen, you cannot retrieve your prior performance. So either carefully review your results or capture screen shots before navigating away.

Integrated Reasoning Interface

The Integrated Reasoning questions open up in a new tab at an entirely different, non-integrated website. The calculator is entirely different than for the main Math and Verbal questions, making the presence of a calculator for those questions all the more puzzling. There is no timing feature for IR, so you must track timing on your own. You can individually check the answer for each question. There is no exam mode or review results screen.

Your responses are saved for each question, and you can jump at any time to any question. The IR section includes the exact same questions as in the 13th Edition of the Official Guide, including the two highly-flawed Two-Part Analysis questions that we described in a prior post.

Bottom Line

The inclusion of an online practice site is an added bonus that previously did not exist for the Official Guides. Because the GMAT is taken on a computer, it is advisable to practice GMAT questions on a computer. For this reason, we recommend practicing the Official Guide questions (other than Reading Comprehension) using the online platform (in Exam Mode), despite the disappointing practice interface. We much prefer the interface of GMATPrep, and wish that the GMAC had instead integrated the Official Guide online practice into GMATPrep instead.

Review of the 2015 GMAT Official Guides

2015 GMAT Official Guides

2015 GMAT Official Guides

The Graduate Management Admission Council (GMAC) released new editions of all three GMAT Official Guides last week. To our dismay, the new editions are almost 100% identical to the editions that they replaced. Other than some very minor wording changes and corrections, the content and questions are the same. This breaks with GMAC’s history of changing 20-30% of the questions for each question type with a new edition of an Official Guide.

The GMAC announced that it will now release new versions of the Official Guides annually. We certainly hope that subsequent editions will revert to the practice of introducing new questions. Otherwise we see no purpose in this move, other than to boost revenue by suppressing the used book market for the Official Guides (and making GMAT instructors buy new copies every year).

Specific Changes in the 2015 GMAT Official Guides

Let’s list the specific changes made from the 13th edition of the main Official Guide, along with some comments:

  • The color used for contrasting text has been changed to a very-hard-to-read lime green. We hope that, in a subsequent release, the GMAC will instead use the readable blue contrasting color that is in the Quantitative and Verbal Official Guides.
  • Page 6 briefly describes the supplementary online videos and practice question tools that are available with the new Official Guides. Pages 4 of the Verbal and Quantitative guides have a similar paragraph. More on the online tools later.
  • Data Sufficiency question #47 (page 279) corrects two minor typos (lack of subscript) in the original printing of the 13th edition, but that were corrected in subsequent printings of that edition.
  • The explanation for Sentence Correction question #77 (page 741) expands significantly on incorrect answer A on slightly on correct answer D.
  • Appendix B – Answer Sheets: Rather than listing the answer sheet for each question type on a separate page (as in the 13th edition), the GMAC now condenses the answer sheets to run continuously. This is admittedly a relatively unimportant section of the Official Guide. But this decision (which saves one printed page of space) degrades the utility of the Answer Sheets.

Appendix A – Percentile Ranking Tables have been updated in all three Official Guides. Perhaps due to printing lead times, the data in these tables are as of July 2013 and are already outdated. You can find the latest percentile tables, released in July 2014, here.

Typos and Incorrect Information

Surprisingly, all three Official Guides contain typos / incorrect information in the first and second chapters. The Official Guide do not reflect current information about Integrated Reasoning. The Official Guides also reference retired editions of the Official Guides. Finally, the timeframe references to the percentile tables have not been updated in all three books. Some simple proofreading should have caught these errors:

  • Main Official Guide – last sentence of page 12: “A score scale for Integrated Reasoning will be available by April 2012 on mba.com.” In fact, a score scale has long since been readily available: IR is scored on a scale from 1 to 8.
  • Main Official Guide – first sentence of page 13: “Appendix A contains the 2011 percentile ranking tables that explain the distribution of GMAT scaled scores across all GMAT test-takers during the period beginning July 2008 and ending June 2011.” Appendix A actually contains the 2013 tables, presumably with data from July 2010 through June 2013.
  • Quantitative and Verbal Official Guides – second sentence of section 1.2 on page 6: “You start the test with two 30-minute Analytical Writing Assessment (AWA) questions …” In reality, one of the AWA essays was replaced with the Integrated Reasoning section in June 2012.
  • Quantitative and Verbal Official Guides – last sentence on page 9: “Appendix A contains the 2007 percentile ranking tables that explain how your GMAT scores compare with scores of other 2007 GMAT test takers.” Appendix A actually contains the 2013 tables.
  • Quantitative and Verbal Official Guides – section 1.9 on page 10 makes three references to the Analysis of an Issue essay that was eliminated from the GMAT in June 2012.
  • Quantitative and Verbal Official Guides – first sentence on page 13 AND first sentence on page 14 suggest that you use the long-since retired 12th Edition of the Official Guide, plus the just retired 2nd Edition of the Quantitative / Verbal guides.

Bottom Line

As mentioned before, the 2015 Official Guides have one important added benefit – online study access. In addition to the 50 online Integrated Reasoning practice questions that were also available with the 13th Edition book, you can now take online practice question sets with the same questions available in the Official Guides. The functionality available is inferior to that available in GMATPrep, but it is a new feature nonetheless. We’ll offer a review of the online tools in our next blog post.

Although the new 2015 GMAT Official Guides are a disappointment, the GMAT Official Guides nonetheless continue to be an incredibly valuable study tool. If you already have the prior versions, there is no need to purchase the new versions. But if you do not yet have the Official Guides, definitely buy these books. Since there is no overlap in practice questions, we recommend that you use all three Official Guides. The Official Guides are the only source for retired real GMAT practice questions, which are essential for effective GMAT preparation.

New GMAT Score Preview and New Official Guides

GMAC logoWe have two important updates from the GMAC to share. First, the GMAC announced today that effective this Friday (June 27), all GMAT test takers can preview their four unofficial scores (Integrated Reasoning, Quantitative, Verbal, and Overall) before they decide whether to report or cancel the scores. The AWA score is not included, since that score is not immediately available due to the human scoring element. Ashok Sarathy, GMAC VP of Produce Management, said, “We are pleased to offer this feature as part of our efforts to make preparing for and taking the GMAT exam easier. The new score reporting feature gives test takers more certainty and control in the testing process and in how their scores are reported to schools.”

How Score Preview Works

Test takers currently must decide to report or cancel their scores without any indication of how they actually performed on the GMAT. If a test taker currently cancels her scores, she will never know what the scores actually were. This change should prove to be a big anxiety relief for test takers. This should also reduce stress levels for test takers during the exam. GMAT examinees will now confidently be able to decide whether to keep or cancel scores, depending on how the scores match up to their goals and expectations. Examinees will no longer need to guess how they performed and then second-guess their decision if they cancel or if they report and receive a lower-than-expected score.

The process works as follows. Immediately after finishing the GMAT, test takers will be shown their four scores. A test taker has two minutes to decide whether to report or cancel. If a test taker does not make a choice, her scores will be automatically canceled. A test taker whose scores are cancelled (either by choice or automatically) will have to option to reinstate the scores within 60 days of the test date for a $100 fee. Since two minutes is not much time, the GMAC wisely recommends that you decide in advance what are the minimum scores you would want in order to report the scores. You can read more about the announcement here.

New Official Guides

The second update is that new versions of all three Official Guides for GMAT Review will release on July 8. If you are just starting your preparations and your test date is far enough out, we suggest that you wait for the new Official Guides. The latest versions will include online access to the questions, and you can create custom practice tests. You can buy the three books as a bundle or individually: Official Guide, Quantitative Guide, and Verbal Guide. We will provide our analysis of the books once we receive and go through our copies.

Question Difficulty in GMAT Official Guides

GMAT Official Guide Question DifficultyStarting with the 11th Edition of the Official Guides, the Graduate Management Admission Council placed questions in order of difficulty. This is a welcome change from prior editions, because students can now choose practice questions at the appropriate difficulty level. Beginning students need not tackle difficult questions that may cause them to feel overwhelmed and frustrated, nor do advanced students need to waste time on questions that are well below their capabilities.

Mysterious Methodology

The methodology that the GMAC uses to assign difficulty ratings to questions remains a mystery, however. Although there is a clear overall correlation between question placement and GMAT Genius’ assessment of difficulty, the correlation is far from perfect and there are many outliers, particularly with math. Let’s consider the Problem Solving section of the GMAT Official Guide (13th Ed.).

Problem Solving Analysis

There are 230 questions in this section, excluding questions in the Diagnostic Test chapter of the book. GMAT Genius assigns difficulty at five different levels: Super Easy, Easy, Moderate, Hard, and Very Hard. To translate this into numbers, we can assign points of 1, 2, 3, 4, and 5 to each of these levels, respectively. With perfect correlation and distribution, we should see the first 46 questions (230 divided by 5) all at a Super Easy level (average difficulty 1.0), the next 46 questions all at an Easy level (average difficulty 2.0), and so on. Instead, here is how we would rank question difficulty:

OG 13E PS Super
Easy
Easy Moderate Hard Very
Hard
Average
Difficulty
1 – 46 11 29 6 0 0 1.9
47 – 92 3 18 23 2 0 2.5
93 – 138 1 10 21 13 1 3.1
139 – 184 0 12 26 4 4 3.0
185 – 230 0 5 25 11 5 3.5
Total 15 74 101 30 10 2.8

As shown in the table, average question difficulty (based on our assessment) does not increase much in the last three quintiles. In fact, the middle quintile is actually slightly harder than the fourth quintile. Surprisingly, we consider five of the top quintile questions “Easy,” including #220, which is supposed to be one of the hardest questions in the entire set. We also consider question #117 in the third quintile “Very Hard,” even though it barely passes the halfway mark. Yet the GMAC considers this question easier than #130, which we rate as “Super Easy.”

Disparity Among Similar Questions

We see this disparity even among similar questions. Questions #178 and #186 both entail overlapping sets, and based on the ordering, the GMAC considers #186 slightly harder than #178. Yet we rate #178 as “Very Hard” and #186 as “Moderate” because the former is a complex application with three groups whereas the latter is a straightforward application with two groups. As another example, consider #137 and #203 that we described in our prior post about repetitive math questions. These two questions are very similar, yet the GMAC considers the latter much harder than the former. By contrast, we rate both these questions as “Hard” and actually consider the latter slightly easier because the numbers are much easier.

Our assessment of difficulty is admittedly somewhat subjective, but probably more realistic than how the GMAC assigns difficulty. Our difficulty ratings take into account our observations of how students tend to find the questions in term of difficulty, the ease of the calculations involved, and the length of the Official Guide explanation, except when the explanation is inefficient or misses a shortcut. For verbal questions, we also take into account the difficulty of the incorrect answers, since process of elimination can be particularly helpful on verbal. Note that our assessment of difficulty skews towards the center; a question would need to be incredibly easy or incredibly difficult to qualify as “Super Easy” or “Very Hard”, respectively. The GMAC most likely has a much greater distribution in its difficulty assignments.

Conclusions

A key takeaway from this analysis is that you should not assume that the Official Guides are an objective measure of question difficulty. Although we don’t know how the GMAC assigns difficulty and would expect a few differences of opinion, we can confidently claim that quite a few questions are ordered incorrectly. So if you encounter a few questions in the Official Guides that are hard for you, it does not necessarily mean that all subsequent questions are beyond your reach. Another implication of this analysis is that the Official Guides do not contain enough difficult practice questions, a complaint we often hear from our advanced students. The GMAC has released two relatively new study products (Exam Pack 1 and Question Pack 1), so let’s hope that Difficult Pack 1 is in the works.

Repetitive Math Questions in GMAT Official Guides

GMAT Official GuidesIn your preparations for the GMAT math section, it is essential that you practice with retired real GMAT questions using the GMAT Official Guide (13th Edition) and the GMAT Quantitative Official Guide (2nd Edition). These two books provide you with a combined total of 430 Problem Solving and 322 Data Sufficiency practice questions.

Repetitive Problem Solving Questions

One interesting observation from our analysis of these questions is the frequency with which some questions closely mirror another question. Due to copyright issues, we cannot reprint these repetitive math questions from the Official Guides. But if you have your copies handy, compare the following sets of Problem Solving questions:

  • 13E #128 (page 170) vs. 2E #132 (page 79): These two questions involving combinatorics are nearly identical, even using the same numbers in the problem and in the first three answer choices (one of which is the correct answer). Only the context changes: one question involves finding the minimum number of colors for a distribution center’s coding, and the other involves finding the minimum number of letters for an experiment’s coding.
  • 13E #194 (page 179) vs. 2E #165 (page 84): Both questions provide three fractions of a total amount and the remaining balance that is unaccounted for, and ask us to calculate the total amount. One question relates to the amount of a trust fund whereas the other involves the number of students in a class, but the numbers within the problems are identical (except that one total is in thousands and the other is not).
  • 13E #124 (page 169) vs. 13E #133 (page 171) vs. 2E #56 (page 69): These three questions all involve calculating the number of pairs that are possible out of a larger group. Two of these questions ask about the number of table entries needed to show the mileage between any two cities, and the third asks about number of games needed so that every team in a league plays each other once. For these types of questions, we teach our students a tabular approach, a combinatorics approach, and a summation approach.
  • 13E #137 (page 171) vs. 13E #203 (page 181): At first glance, these two word problems seem unrelated. But the setup for both problems is identical: we have an unknown price and quantity, and when one goes up by a specified amount the other goes down by a specified amount in order to generate an equivalent revenue amount.
  • 13E #111 (page 167) vs. 13E #170 (page 176): In both cases, we have a terminating decimal in the form of 1 / (2^x * 5^y) where x and y are specified exponents. Both questions entail counting digits.
  • 13E #95 (page 165) vs. 13E diagnostic #13 (page 22): Both questions entail one positive integer divided by another, resulting in a quotient and a remainder equivalent to .12. Our objective is to use the .12 to deduce the value of the divisor in one question and to identify a possible remainder in the other question.
  • 13E #45 (page 158) vs. 2E #57 (page 69): Both problems give us a quadratic equation using the variable x and a constant k. Given one root of the quadratic, we must find the other solution in one problem and the value of k in the other problem.

Repetitive Data Sufficiency Questions

Although the above are the most obvious examples of repetition in Problem Solving, there is much more repetition of concepts across questions. We also can find examples of repetition within Data Sufficiency, albeit to a lesser extent. As two obvious examples, compare the following sets of Data Sufficiency questions:

  • 13E #2 (page 275) vs. 13E #21 (page 276): These two questions have identical setups, although with different numbers in different contexts. In both questions, statement 1 gives us what percent of women have a certain characteristic and statement 2 gives us what percent of men have the same characteristic. The questions both ask what percent of the total are women with that characteristic.
  • 13E #57 (page 280) vs. 13E #59 (page 280): In both cases, we have two different denominations (of bills in one question and of gift certificates in the other). Statement 1 has an identical setup in both questions – the maximum number of the smaller denomination. In #57, the initial information tells us the minimum number of the larger denomination and statement 2 tells us the total value of both denominations combined. In #59, the initial information and that given in statement 2 are swapped.

Conclusions

Why does this repetition happen? Since the GMAT tests a finite number of concepts, these concepts will inevitably appear repeatedly in various forms. But since the GMAC must produce a vast number of questions each year to ensure a fair testing environment, one way to make the question development process more efficient is to borrow heavily from other questions. We also see concepts applied repetitively in Verbal questions, but the questions themselves are not as obviously duplicative as the Math questions that we’ve discussed.

What is the implication of this? One of our “6 Habits of Highly Effective GMAT Students” is to watch out for patterns. As you work through many practice GMAT problems in the Official Guides and elsewhere, you will inevitably encounter similar concepts. With sufficient practice, you will be able to identify the approaches that are most relevant to a given problem. Of course you should not blindly follow the same methodology used on another problem, since the concepts may be applied differently. But the more adept you are at quickly recognizing the relevant approaches to apply to questions on test day, the better your GMAT score will be.

Like Versus Such As

Like vs Such AsIdioms are one grammatical component of GMAT sentence correction problems. Furthermore, the GMAT tests meaning, part of which is appropriate word choice. One issue that the GMAT has previously tested is the usage of like versus such as. When giving an example, we should use such as: John collects pictures of sports cars made by companies such as Lamborghini and Maserati. When indicating similarity, we should use like: A giraffe’s neck is like that of a brachiosaurus.

Difference Between Like and Such As

Although like has come to be used synonymously with such as in common usage, there is an important distinction that is too often overlooked. In particular, like implies similarity but exclusion whereas such as implies inclusion. Using like is appropriate only if the action pertains to nouns similar to our referenced noun but specifically excludes the referenced noun. As an example: Movies today often feature heroic actors like John Wayne. This usage is correct because movies today feature actors similar to John Wayne, but do not feature John Wayne himself. On the other hand, we could say: Movies today often feature heroic actors such as Brad Pitt. In this sentence, such as is appropriate because Brad Pitt is both an example of a heroic actor and is included in the list of heroic actors today. Here is an interesting article from Grammar Girl that expands on this point.

Incorrect Usages of Like

In October alone, I have come across at least 100 incorrect usages of the word like in the context of providing an example. In every one of these instances, such as would be a better choice. To me, hearing the work like used in this manner is like hearing fingernails scratching a chalkboard. Here are just a few examples that I have come across, including a couple which appropriately use such as:

  • An October 8 article about Samsung in The Wall Street Journal: “Samsung has evaluated startups such as Unity Technologies … and Green Throttle Games.” Yet the next sentence of the same article states: “It has also considered gaming pioneer Atari Inc., which Samsung could have used to offer classic games like Asteroids and Ping Pong.”
  • A Google help page for its AdWords product: “Choose words or phrases relevant to your product or service so your ads appear when customers use those terms to search on Google or search partner sites, like AOL.”
  • An article in the October issue of Entrepreneur magazine about the OwnerListens app: “After 15 years of building companies such as Hotbar.com and SmartShopper.com, Oren Dobronsky checked out of technology and into hummus.”
  • The next article in the same issue of Entrepreneur magazine, written by the exact same author: “Ephraim signed on with London-based GoSquared, an analytics platform designed to demonstrate how people use a site, tracking key information like where individual visitors are from, what brought them to the site and how they view a page.”
  • An earthquake preparedness flyer from ReadyOC: “Your bucket list consists of basic items you’ll need in case of emergency – like an earthquake or wildfire.”
  • An article about cruising from the November/December issue of AAA magazine Westways: “On some luxury lines, items like bar drinks, tips, and even shore excursions are included.”
  • The featured article in the Personal Journal section of the October 30 issue of The Wall Street Journal: “Marc Forgione creates a tableside ‘cloud’ of truffle broth with dishes like squash ravioli and rabbit Bolognese at his New York restaurant.”
  • An article about study-abroad programs, also in the October 30 issue of The Wall Street Journal: “But students might be missing out on some important life experiences, like learning to be self-reliant and adaptable…”
  • The privacy policy of another GMAT preparation company: “Our site’s secure registration form requires users to give us contact information, like their name and email address.” “We do not store financial information like credit card numbers or personal information like social security numbers on this site.”

Correct Usages of Like

Does the word like ever get used correctly? Here are two usages that appropriately convey that one noun is similar to another. This is typically how we see the word like used correctly on GMAT Sentence Correction.

  • An article in the October 28 issue of Forbes about the 50 best small companies: “Like j2, Stamps.com rediscovered its greatest strength in a core business.”
  • An article in the October issue of Inc. magazine: “Innovative culture is like karaoke.”

Like a sunny day, all good things, such as this article, must come to an end. So I’ll leave you with this final thought: When taking a standardized test such as the GMAT, avoid using the word like to indicate an example.

Fractions are Critical to GMAT Math

Fractions are critical to GMAT mathAn interesting article on fractions appeared this week in the Wall Street Journal. You must be thinking: fractions? interesting? Well, it’s interesting at least for those of us who teach the GMAT.

According to the article, “national tests show nearly half of eighth-graders aren’t able to put three fractions in order by size.” Can you? Here’s a Problem Solving question from the 2nd Edition of the GMAT Quantitative Official Guide.

Which of the following is greater than 2/3?
(A) 33/50
(B) 8/11
(C) 3/5
(D) 13/27
(E) 5/8

Methods to Compare Fractions

By definition, only one answer can be correct, and therefore only one answer can be greater than 2/3. So we are essentially looking for the biggest of these five fractions. There are two common methods by which to compare fractions: find a common denominator and then compare the numerators OR convert the fractions into decimals. Two more subtle approaches are comparing the fractions to a point of reference (such as 1/2) and finding a common numerator in order to compare the denominators.

Solution to Problem

For this problem, finding a common denominator seems messy. We can quickly eliminate (D) by noting that 13/27 < 13/26 = 1/2 < 2/3. For the remaining answers, it’s best to convert them into decimals. In order to save time, we don’t need to convert them all into decimals. We just need to find one that is greater than 0.6666 (the decimal equivalent of 2/3). So we should start with whichever answer seems the biggest.

GMAT Genius recommends that you memorize the fraction-to-decimal conversions for halves, thirds, fourths, fifths, sixths, eights, ninths, tenths, and elevenths. If you know these conversions, we can quickly identify (B) as the correct answer. 1/11 = 0.090909. To find any other eleventh, just multiply the numerator by 9. So 8/11 = 0.727272, which is clearly more than 2/3. For the record, (A) 33/55 = 0.66, (C) 3/6 = 0.6, and (E) 5/8 = 0.625. But again, once we have identified (B) as the correct answer, we should not spend our time with these additional conversions. Let’s save those precious few seconds for other problems.

Benefits of Fractions

Although this is admittedly an easy question by GMAT standards, fractions are essential to the GMAT math section. Fractions tend to make calculations easier than decimals, because numbers often conveniently cancel out when using fractions. Fraction calculations can appear directly and indirectly on all types of GMAT math problems, not just on basic arithmetic problems. As Dr. Bob Siegler of Carnegie Mellon University states in the Wall Street Journal article, “If you don’t understand fractions, it’s literally impossible for you to understand algebra, geometry …”. So be sure to study your fractions!