Quant Demystified

Yogish Lavanis is the co-founder of Valued Epistemics Pvt Ltd, the company offering GREedge programs. He heads the Student Facilitation team at GREedge.com and is considered “Star Teacher” capable of capturing students’ spirit of learning. Yogish is able to transform the learning experience into a dynamic and student-centered experience where a student can attain success. Through his extensive research on effective teaching methodologies, Yogish offers a realistic glimpse and practical application of how good teaching can transform students’ learning – a fact that will be seconded by almost all students who have achieved through GREedge.com. In his column, Yogish writes about all the questions that haunt students… starting from “What is the GRE?” to “How do I select the right university for me?” and everything else in between.

As promised, this time I will try to explain the Quantitative section of the GRE to you.

This section evaluates basic mathematical skills. It examines your ability to interpret numerical data, apply mathematical concepts to solve worded problems and also your knowledge of basic math concepts.

The test comprises 28 questions, which should be answered in 45 minutes. The maximum score that you can achieve is 800. Like as in the Verbal section, the test in the Quantitative section is also adaptive. You will be given one question at a time. The difficulty level of the question changes based on whether the answer to the previous question was correct. It increases as your accuracy increases and drops as your accuracy drops. Thus, your final score depends not only on the number of correct answers but also on the level of difficulty of the questions that you answered correctly.

In an adaptive test, since you get one question at a time, you do not have the flexibility that you have in a paper test. In a paper test, you have the option of solving questions in any order. This helps you build confidence by first solving questions you are comfortable with. You, therefore, need to adopt a different strategy to take an adaptive test like GRE.

The question that pops up next could be of any type; you have no control over the order of the questions. So, it is important to develop mastery in solving all types of questions and in all topics of maths prescribed for the Quantitative section.

The questions in the Quantitative section of the GRE fall into the following broad areas: Arithmetic, Algebra, Geometry, Data Interpretation, basic Statistics, Probability-Permutation-Combination and Applied Mathematics. Applied Mathematics comprises situations where maths is applied in simple day-to-day situations, such as Profit and Loss, Venn Diagrams, Distance-Speed, Work/Effort estimation, etc. The level of mathematics is typically of the high-school level.

Topics such as Trigonometry and Calculus, though taught at high school level, are not in the scope of the Quantitative section of GRE.

In GRE, there are three forms of questions:

  • Worded numeric questions, where a problem is described in words and a certain solution is desired. You are expected to solve the problem by application of mathematical concepts

  • Data Interpretation questions, where you are provided with graphs. Questions based on these graphs expect you to interpret the graphs and draw correct conclusions from them.

  • Data comparison question: You are provided with two statements. You are expected to determine the numerical value of each statement an compare them.

Here are examples of each type.

Worded numeric problem: here is an example from Work/Effort estimation.

farmer-with-pitchfork

Farmer Joe started harvesting operation on a patch of cultivated land. He could have completed it in 100 min. But after 50 mins he decided to take a break. His assistant Bill took over. Though Bill could have completed what was left to be harvested in 40 mins, he stopped after 20 minutes and handed over the operation to his trainee Chuck. Chuck worked for 30 minutes and the entire field was harvested.

(Try to solve this question. The answer is 12 : 15: 10)

Example of a Data Interpretation question: Answer the question based on the data provided in the graph and tables below:

Question: Which country has the maximum number of people listening to music through ipods ?

table1

di

(answer USA)

Data comparison questions: You are provided two statements. Each statement can result into numerical values. You are required to compare the two values.

P@Q is defined as pq

qp

Column A

Column B

18@17

17@18

Determine if Column A > Column B, Column A < Column B, Column A = Column B, or the relationship can not be determined.

As I mentioned, make sure you that you develop the requisite amount of knowledge and the problem solving skills in all that the areas that are relevant to the quantitative section. A word of caution for those from Science and Engineering backgrounds. Though you might have been exposed to more advanced topics of maths as part of your undergraduate studies, do not under estimate the preparation needed for this section. To get that perfect 800, you need to be sure that you achieve high accuracy on those 28 questions and that too in 45 mins. That gives you about 1.5 min per question. If you are not well prepared, an odd difficult question could slow you down. So it becomes important that you have trained yourself well on topics and have the real sharp problem solving skills on the day of the test. Very much like an ace shooter on the day of the finals of a tournament.

If you been out of maths for a fairly long time, it is better to start early. Before you start on with the preparation on the GRE type of tests, revisit relevant topics of maths that you were taught at high school level. Refresh your understanding of the concepts and solve basic problems based on them. This exercise will not take much time but can help in laying a good foundation over which your preparation of GRE can rest.

I would recommend a three phase study plan. In the first phase, expose yourself to all the relevant topics of maths and all the corresponding question types. In the process, you should have mastered all the necessary formulas, concepts, approaches and developed your arsenal of problem solving skills. In this phase do not worry about your speed or the time that you take to solve questions. It is alright to take a few minutes more as long as it helped you master something new.

In the second phase, focus on speed. Solve more and more problems spanning over all topics to develop speed and your confidence. In a learning session, you may solve a set of questions of a particular topic. This will help you deepen your understanding of the concepts and sharpen your intuition, logic and problem solving skills.

In the third phase, develop your time management. Solve as many online adaptive mock tests as you can. Practice to complete the test in the stipulated 45 mins with a high level of accuracy.

Besides knowledge of maths, ensure that you consciously develop a set of related skill sets.

  • Learn tricks that enable you to perform quick numeric computation (note you can not use electronic calculators in GRE).

  • In worded numeric questions, it is important to develop the skills of converting worded statements into the right mathematical equations. As you practice, make sure you become extremely familiar with the typical language used in the statements.

  • Questions with Geometric diagrams involve development of strong visualization skills. You should be able to quickly detect standard geometric shapes (like equilateral triangles, 30-60-90 triangles, squares etc) so that you can make use of the standard properties or formulae of these shapes and solve the question. Here is an example.

In the figure, two concentric circles with centre O and radii 8cm and 4cm have parallel chords PQ and RS. Find the area of the figure PQRS.

moz-screenshot-2

1. The question wants you to determine the area of PQRS, which is a trapezium.  Your are not sure at this stage if this a regular trapezium.  You probably do not remember formula for area of a trapezium.

2. Your visualization should indicate that  Area of the trapezium =  Area of triangle OPQ  – Area of triangle ORS.  We know that formulae for area of triangle are well understood. So you just need t o determine the area of these two triangles.

3. Now focus your attention on triangle, ORS.  Is it a specific type of triangle (equilateral, right, isoceles). A bit of visualization with make you realize that OPQ is an equilateral triangle.  (think) Similarly, ORS is also an equilateral triangle.

4.  With this information, it is easy to determine the area of the two triangles if you just know the formula for area of an equilateral triangle ( area of an equilateral triangle = √3 S^2/4 ;  where S is the side of the triangle)


In summary, the quant section is just based on mathematics taught at the high school level. Through systematic preparation, ensure that you develop all skills that I mentioned here. Your preparation should be such that you should not encounter a question in the actual test that tells you – “hey I have not seen a question of this kind earlier !!! ”

Thats when you know you are ready for the Quant section of the GRE.

Best wishes….

Shalu Gupta on GREedge.com

This is an  interview with a student of GREedge.com Shalu Gupta, a working professional who got a score of 700 in GRE verbal. This interview is taken on a conversational mode, where G refers to GREedge.com and S refers to Shalu.

G: “ Shalu , You are the second highest score getter from GREedge.com in the verbal section, how does it feel??”
S: “ Obviously it feels great to get such a score…I was expecting over 600, but getting 700 was too good!!”

G: “ When did you actually start preparing for GRE?”
S: “ I joined GREedge.com in March, 3 months before my GRE. Before that I was preparing from Barron’s and Kaplan’s…but there was no focus.

G: “ Ideally how much time did you spend per day for preparing??”

S: “ I was already working when I planned for GRE. So finding time was always a task for me. My office hours were from 9:30 am to 6:30pm. At times I had to stay back till 9:00pm…as a software developer my job included continuous involvement with my work…but I managed to steal some time from my work and took at least 2 sessions from GREedge.com. After coming back home I spent at least 2 hours time for preparation. So in total I think I had spent 4 hours per day.”

G: “ How did you tackle the word list for GRE…its quite long…what was your strategy?”
S: “ I had finished the word list from Barron’s before I started on with GREedge.com. Then the Word Bank from GREedge.com was also a useful material. It acted as a refresher for me…apart from this I had a vocab software which taught the words through both audio and visual materials…all these helped me in developing a satisfactory vocabulary.”

G: “ How useful were the feedbacks(GMCs) given to you by GREedge?”
S: “ The GMCs given by my SFA (student facilitator and Analyst) acted as a performance tracker for me. His useful tips on honing my skills, his analysis of the error types in me and the remedies provided helped me to achieve such a level where I became less prone to errors. He also boosted my moral and gave me confidence during the days when GRE was closing in…I feel that the feedbacks too played a pivotal role in determining my score.”

G: “ What was the response from your friends after they heard of your GRE score..?”
S: “ My friends were like..’ oh my GOD..how did you do that??’ …they were also curious to know about my study style and the materials that I followed…”

G: “ After this stupendous success, are you going to refer GREedge.com to some of your friends?”
S: “ I have already done so and will keep on doing so…I have felt the difference with GREedge.com and I want my friends to feel the same…Thanks a lot GREedge.com.”

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