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PDF archive of questions from GMATQuantum blog

The pdf file above contains all of the questions published in the GMATQuantum blog. Please download the file and then open it in Adobe Acrobat Reader for all of its features to work properly.

GMAT Strategies: Articles from GMATQuantum Blog


GMATQuantum's Review: Official Guide for GMAT Review 2018

As in the past the Official Guide for GMAT Review 2018 comes with incremental changes to the content. My review here is exclusively focused on the Quantitative Reasoning section of the guide. In spite of the incremental changes, the guide remains a must have for any student preparing for the GMAT, and is a good starting point towards serious GMAT preparation.

If you happen to already have a copy of the 2017 or the 2016 Official GMAT guide, then there is no reason to spend money on buying this. Instead, I would recommend you to spend this money on additional official GMAT resources such as GMATPrep Question Pack 1 and Exam Pack etc.

The 2018 guide has 15 percent new questions and a total of 61 new questions in the quantitative reasoning section. In a departure from the past, GMAC decided to officially release the entire list of new questions in the 2018 Official GMAT guide and how the changes compare to the 2017 Official GMAT guide.

Problem Solving: 3, 5, 6, 16, 22, 23, 24, 26, 33, 34, 40, 42, 50, 53, 55, 60, 68, 69, 72, 79, 81, 85, 90, 96, 98, 104, 122, 125, 139, 140, 151, 173, 201, 224, 229.

Data Sufficiency: 233, 258, 260, 262, 266, 267, 273, 274, 276, 277, 278, 282, 284, 287, 288, 292, 293, 300, 306, 313, 326, 334, 339, 376, 382, 391.

The following is a repeat of what I have said about the older guides and unfortunately it continues to hold true.

Here is my list of issues with the last three or four editions of the Official GMAT guide:
  1. Obsolete and inappropriate diagnostic test: The diagnostic test in the Official guide has been the same since its introduction in the 11th edition of the GMAT. The diagnostic test for quant consists of 48 questions, 24 each in the category of problem solving and data sufficiency. Almost all of the questions are on the difficult side, and this ends up scaring students who are just starting out preparing for the GMAT. My long standing recommendation to students is to ignore this diagnostic test. The test is too difficult and does not serve the purpose of a diagnostic test, instead it ends up creating fear in students who are just starting out. A proper diagnostic test should consist of questions that range in difficulty level from easy to hard. Also, it would be helpful if the diagnostic test gave students a rough estimate of their initial score. I believe GMAC has the knowledge and tools to improve the diagnostic test, it is just a matter of getting it done. Some might argue that the full length practice tests in the free GMATPrep software should serve as a better gauge of an initial diagnostic test. However, I don't like subjecting students to a full length computer adaptive test early in their preparation. Most students end up doing horribly on GMATPrep in their initial stages, and it just causes more stress than getting any meaningful data from it.

  2. Drop all older GMAT questions: The current official GMAT guide consists of about 30 percent questions that are from the old paper and pencil format of the GMAT test (more than 20 years ago), and the questions are of lower average difficulty and do not accurately reflect the current content on the GMAT test. These questions are now outdated and should be replaced with GMAT questions from recent administrations.

  3. Remove overlap with GMAT Focus diagnostic tests: There are several questions in the current Official Guide that also pop up on the GMAT Focus quantitative diagnostic tests. Here I have done the work for GMAC and listed these questions, all they have to do is to ensure that they don't appear in the 2018 GMAT guide.

  4. Organize questions in increasing order of difficulty: GMAC claims that the questions in the official guide are in increasing order of difficulty. This is broadly true, however there are plenty of questions that do not follow the trend. I am certain that GMAC has the detailed statistics of each question, for example the percent of students that answered a particular question right, and they could easily use that data to rearrange the questions by correct difficulty level.


GMAT Problem Solving 85: Sequences with repeating patterns

Try this GMAT problem solving on sequences that have a repeating pattern.

Let \(a_1 , a_2 , ...\) be a sequence for which \(a_1=2\), \(a_2=3\), and \(a_n=\dfrac{a_{n-1}}{a_{n-2}}\) for each positive integer \(n \ge 3\). What is \(a_{2006}\)?
  1. \(\quad \dfrac{1}{2}\)

  2. \(\quad \dfrac{2}{3}\)

  3. \(\quad \dfrac{3}{2}\)

  4. \(\quad 2\)

  5. \(\quad 3\)


GMAT Problem Solving 84: Absolute value identity

Try this GMAT problem solving on absolute values. This problem can certainly be done by plugging in specific values for \(x\). However, I would like you to also try solving it algebraically which involves using absolute value identity and how to remove the absolute value sign of an algebraic expression. These two steps are often seen on the GMAT, especially in data sufficiency where you need to be comfortable with algebraic manipulation.

Given \(x<0\), \(|x- \sqrt{(x-1)^2}|\) equals
  1. \(\quad 1\)

  2. \(\quad 1-2x\)

  3. \(\quad -2x-1\)

  4. \(\quad 1+2x\)

  5. \(\quad 2x-1\)