In this third post of this series of exclusive previews of the 2017 GMAT Official Guides, we now turn to the math section of the main Official Guide. We will focus on how the 2017 GMAT Official Guide differs from the 2016 edition in terms of math question difficulty and math concepts.
Problem Solving – Difficulty
Both the 2017 and 2016 editions of the GMAT Official Guide contain 254 Problem Solving questions, including 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 towards Easy difficulty. Part of this change resulted from the GMAC downgrading 8 questions from Medium difficulty (in 2016) to Easy (in 2017).
| Difficulty | 2017 | 2016 | Change |
|---|---|---|---|
| Easy | 82 | 63 | +19 |
| Medium | 55 | 60 | (5) |
| Hard | 117 | 131 | (14) |
| Total | 254 | 254 | — |
A total of 36 new Problem Solving questions, which we have never seen before, appear in the 2017 GMAT Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 18 / 8 / 10. This is in lieu of 36 questions from the 2016 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 7 / 5 / 24. We are disappointed to see that Hard difficulty has a net loss of 14 questions, although we would rate most of the 24 removed Hard questions as actually Medium difficulty. Let’s further break down how each of these difficulty categories has changed.
Easy Problem Solving
Additions:
18 new questions
8 downgraded from Medium
Subtractions:
7 questions removed
Net change: +19 questions
Medium Problem Solving
Additions:
8 new questions
Subtractions:
5 questions removed
8 downgraded to Easy
Net change: -5 questions
Hard Problem Solving
Additions:
10 new questions
Subtractions:
24 questions removed
Net change: -14 questions
Problem Solving – Concepts
Let’s now consider changes in the concepts of the 36 new (in 2017) and the 36 removed (from 2016) 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 | 2017 | 2016 | Change |
|---|---|---|---|---|
| Arithmetic | Basic | 2 | 0 | +2 |
| Arithmetic | Divisibility/Factors/Mult. | 1 | 2 | (1) |
| Arithmetic | Exponents & Roots | 1 | 1 | — |
| Arithmetic | Fractions & Ratios | 3 | 6 | (3) |
| Arithmetic | Percents | 5 | 6 | (1) |
| Algebra | Inequalities | 2 | 0 | +2 |
| Algebra | Linear Equations | 2 | 3 | (1) |
| Algebra | Quadratics | 2 | 2 | — |
| Algebra | Simultaneous Equations | 2 | 2 | — |
| Algebra | Variables in Answers | 3 | 1 | +2 |
| Geometry | Circles | 1 | 1 | — |
| Geometry | Coordinate | 0 | 1 | (1) |
| Statistics | Averages | 2 | 3 | (1) |
| Statistics | Other | 3 | 1 | +2 |
| Word Problems | Combinatorics | 1 | 0 | +1 |
| Word Problems | Functions & Sequences | 1 | 1 | — |
| Word Problems | Groups/Sets | 1 | 2 | (1) |
| Word Problems | Probability | 2 | 2 | — |
| Word Problems | Rate & Work | 2 | 2 | — |
Although we cannot draw definite conclusions from this data about question composition on the GMAT, what stands out most is the decrease in fractions & ratios questions.
Data Sufficiency – Difficulty
Both the 2017 and 2016 editions of the GMAT Official Guide contain 198 Data Sufficiency questions, including 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 away from Hard. No questions have been reclassified in terms of difficulty.
| Difficulty | 2017 | 2016 | Change |
|---|---|---|---|
| Easy | 50 | 46 | +4 |
| Medium | 51 | 41 | +10 |
| Hard | 97 | 111 | (14) |
| Total | 198 | 198 | — |
A total of 26 new Data Sufficiency questions, which we have never seen before, appear in the 2017 GMAT Official Guide, with difficulty ratings of Easy / Medium / Hard as follows: 9 / 12 / 5. This is in lieu of 26 questions from the 2016 edition that have been removed, with difficulty ratings of Easy / Medium / Hard as follows: 5 / 2 / 19. We are disappointed to see that Hard difficulty has a net loss of 14 questions, although we would rate most of the 19 removed Hard questions as actually Medium difficulty. Let’s further break down how each of these difficulty categories has changed.
Easy Data Sufficiency
Additions:
9 new questions
Subtractions:
5 questions removed
Net change: +4 questions
Medium Data Sufficiency
Additions:
12 new questions
Subtractions:
2 questions removed
Net change: +10 questions
Hard Data Sufficiency
Additions:
5 new questions
Subtractions:
19 questions removed
Net change: -14 questions
Data Sufficiency – Concepts
Let’s now consider changes in the concepts of the 26 new (in 2017) and the 26 removed (from 2016) 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 | 2017 | 2016 | Change |
|---|---|---|---|---|
| Arithmetic | Basic | 5 | 2 | +3 |
| Arithmetic | Divisibility/Factors/Mult. | 1 | 0 | +1 |
| Arithmetic | Exponents & Roots | 3 | 2 | +1 |
| Arithmetic | Fractions & Ratios | 1 | 1 | — |
| Arithmetic | Percents | 3 | 2 | +1 |
| Arithmetic | Pos/Neg & Odd/Even | 1 | 4 | (3) |
| Arithmetic | Primes | 1 | 0 | +1 |
| Algebra | Linear Equations | 1 | 0 | +1 |
| Algebra | Quadratics | 1 | 3 | (2) |
| Algebra | Simultaneous Equations | 1 | 2 | (1) |
| Geometry | Circles | 0 | 2 | (2) |
| Geometry | Triangles | 3 | 1 | +2 |
| Geometry | Other | 1 | 0 | +1 |
| Statistics | All | 1 | 0 | +1 |
| Word Problems | Groups/Sets | 2 | 3 | (1) |
| Word Problems | Probability | 1 | 1 | — |
| Word Problems | Revenue/Profit/Interest | 0 | 3 | (3) |
Although we again cannot draw definite conclusions from this data about question composition on the GMAT, what stands out most is the decrease in odd/even and revenue/profit concepts .
Removed Questions
Here is the list of the math questions that have been removed from the 2016 edition of the GMAT Official Guide. We’ll publish a list of the new math questions in the 2017 GMAT Official Guide after it publicly releases.
Problem Solving – 36 questions removed:
26, 34, 37, 40, 41, 47, 54, 65, 72, 79, 80, 103, 110, 111, 150, 157, 161, 169, 176, 179, 180, 184, 186, 187, 194, 197, 198, 199, 200, 202, 203, 207, 208, 209, 227, 228
Data Sufficiency – 26 questions removed:
1, 3, 9, 17, 33, 44, 65, 74, 78, 81, 109, 113, 131, 139, 140, 141, 150, 151, 154, 158, 159, 165, 166, 170, 173, 174
Summary
In the 2017 GMAT Official Guide, the GMAC has replaced a total of 62 Quant questions, representing just over 15% of the questions (excluding the Diagnostic Exam section). The changes in this edition are far less significant than the changes we saw between the 2015 to the 2016 editions of this book. Nonetheless, what stands out is the net loss of 28 Hard Quant questions, as rated by the GMAC. GMAT Genius will continue to offer detailed analysis of the 2017 GMAT Official Guides in the coming weeks. Stay tuned!