How to prepare for CAT 2020 using Arun Sharma's book on Quantitative Aptitude (QA)?

I appeared for the CAT exam in 2017 and scored 99.09 percentile. As a non-engineer, I had a fear of the QA section of CAT. But now that I've crossed that bridge, I want to share how self-preparation books can be used to prepare for the QA section from the scratch. Disclaimer: I used the Fifth Edition of Arun Sharma's book (image shown below) and this is not an endorsement post. If you're a regular reader of this blog, you would know that my intention behind this post is to share insights on 'how to use this book'. If you wish to use any other self-preparation book, you should definitely do so, the points mentioned in this post can still be of use.

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Who should use this Book?

Arun Sharma's book on QA should be used by those who need:

1. Basics: Someone who is at the beginner level of QA preparation will stand to benefit from the detailed concepts and explanations presented in the book.

2. Step-by-Step Preparation: It is a good guidebook for QA preparation which helps you assess how much you need to focus on each chapter.

3. Large Question Bank: If you haven't enrolled for a coaching, chances are you might be lacking the study material to practice QA questions.

Some people recommend using online resources than physical books for QA preparation because they claim that the pattern of the CAT exam has become more analytical in nature and is no more based on formula questions. In my opinion, having sound basics is the key to cracking this section, no matter how analytical the questions may become. So, for a student whose mathematics is not as good as that of engineers, using physical books, that elaborate the concepts in detail and provide numerous questions to go through, is a better option.

Here is a video on how I used this book during my preparation along with a formula book that I created:

Components of the Book

Under this section, I'll be sharing the flow of the book and discussing how each component can be used. The views presented are my own, so you may choose a different way which suits you:

Index

Don't just skip the index, it is probably one of the most important part of any book. To make use of this space, note down the number of questions (level of difficulty wise) in front of each chapter. E.g. In front of the chapter 'Averages' write: 84/45/49 signifying 84 questions of difficulty level 1, 45 of difficulty level 2 and 49 of difficulty level 3.

Now, make use of this link by 2IIM which has provided a detailed weight allocation to different topics of QA and has suggested which chapters frequently repeat themselves in the CAT exam. Using the number of questions given in your self-preparation book and their weightage in the CAT syllabus, you can create a timeline for CAT preparation. This will help you use the index as a proxy of how many chapters can you finish in a week basis the number of questions it has.

Developing your Calculations

This section provides some great tricks in the book to speed-up your calculation. My suggestion would be to read this section in your spare time and not before beginning your preparation. This is because it is a continuous activity you're supposed to do to increase your calculation speed. You can also make use of the tips I've shared for increasing calculation speed along with it.

Back to School

This is an assessment test given in the front of each block to understand your existing level of comfort with the chapters of the block. An analysis of this test shows how much you should focus on the chapters of the block (i.e. up to which level should you solve it). In my personal opinion, you should skip this test. There are two reasons behind it:

1. It's not a good idea to jump to the questions of the assessment tool without brushing up with any concepts or basics.

2. You should aim to focus on all the chapters evenly even if you find out that you're good at certain topics. This is because the exam is unpredictable, so the questions may be twisted.

Core Concepts

There are some concepts given in the beginning of each block as well as the chapter just before the exercises. This is one of the most precious resources of this book and you should spend due amount of time on reading it, grasping it and taking notes in your formula book. Here is an example of how I used to mark the different tricks and formulas from both the core concepts as well as the question banks that follow it:

There are two resources which help the most in building your base for the QA section of CAT. This resource is the first one (the second one is revealed ahead). This is where you will find those gems of shortcuts to be used during the CAT exam.

While studying the Core Concepts, I used to highlight the tricks and formulas with different colours so that it is easier to record it later in the formula book and so that I can re-read the core concepts during the final revision and get a grasp of both tricks and formulas separately as well.

Solved Questions

These are some questions that are solved and illustrated just before the exercises of different levels begin. This is a great tool to go through because it shows the approach the author uses while solving the questions. It helps in eliminating unnecessary steps. I used to read the question, try solving on my own and then check if my approach matched with that of the author. These questions are very few in number (8-10) so you can spend some time on them.

Level-wise Questions

There are three levels in Arun Sharma's book also called Levels of Difficulty (LOD): 1 stands for easier questions, 2 stands for moderate questions and 3 stands for hard questions. These questions and their levels can be translated as follows:

• LOD 1: These are mostly formula-based questions and can be solved with ease if you've read the core concepts in detail. About 8-10 questions in the QA section of the CAT exam are of this type.

• LOD 2: These are application based questions which make use of the formula but involve its analytical application or a certain tweak to make the question tricky. Some questions under this category are unique and cannot be solved unless you know the trick behind them. Majority of the questions in the CAT exam are of this type.

• LOD 3: These are complex questions that require you to think really hard and work out the problem by often making use of multiple concepts. Only about 2-5 questions in the CAT exam are of this type.

While preparing for the CAT exam using the Arun Sharma's book, you can skip LOD 3 questions. They don't frequent in CAT much and even when they do, they take up so much time to be solved offering the same amount of marks as an easier question. Only if you've completed your entire syllabus and are left with nothing else to do, you can solve them out of boredom.

You need not trust me on this. I can share a Quora answer by the Author Arun Sharma, who himself states that:

Do not focus on solving each and every question of LOD 3 as a conventional Mathematics problem solving objective. Instead, try to use the Level 3 questions to learn about how complexities can be created on a particular chapter.

Now, there are different ways in which people make use of the LOD 1 questions and LOD 2 questions. Initially during my preparation, I tried solving LOD 1 and LOD 2 of each chapter while marking the chapters completed. However, somewhere in the middle of my preparation, when I started taking more mocks, I realized that my basics need to be done by July end. That's when I decided to solve the LOD 1 of the remaining chapters first and then solve the LOD 2s depending on which chapters needed more practice.

You can follow either of the strategies and even change them mid-way basis how your preparation is going. But, in my opinion, solving the basics (LOD 1) first will help you feel more prepared for the mocks. If you realize that any chapter lacks depth during the mocks, make sure to revisit the concepts and attempt its LOD 2s.

Solutions & Explanations

Remember that I stated earlier in this post that there are two resources that help the most in building basics. This is the second resource. Sometimes, you may not be able to solve the QA questions back-to-back. Please don't feel demotivated. The idea is to learn how to solve, not to be already good at solving. If you often feel demotivated during practicing QA, I'd suggest you to try this approach.

Now, in order to use this resource in the best possible manner, you should take care of two things:

1. Never look at the solution immediately after attempting the question. First attempt a set of questions (let's say 10-20 questions in a go) by spending a stipulated time on each (I used to spend about 5 minutes/question at max after which I used to skip it).

2. After attempting, take a short break. Then, look at the detailed explanations (and not only the answer key) to understand how each question was to be solved. Make sure you also read the explanations of the questions you got correct. This will help you learn the shortest methods which were to be used to solve those questions.

3. Mark important formulas, tricks, shortcuts revealed in the explanations and note them down in your formula book. If you find that a question is unique, put it under a separate head for your revision plan.

This part of the book is as important as the detailed analysis of the mock you receive after attempting it. I've shared in an earlier post on IIM Case Studies that mock analysis is way more important than taking the mocks. Similarly, attempting the questions from the exercises is incomplete if you don't follow it up by a thorough analysis of the solutions.