Chapter 1 | Fundamentals of Data Sufficiency | BMM10236 | 1 of 40

Data sufficiency is one area in CAT which serves the twin purpose of scoring high and saving time, only if handled with care.

Students spend a considerable amount of time in mastering the concepts in math during the preparation. These concepts can

be utilized for solving the problems on DS with ease and efficiency.

Fundamentals of Data Sufficiency

Can you solve22 934x 536 895= No (or Yes)?

Your aim should be to score full marks on Data Sufficiency questions. Approaching these problems properly will help you

achieve a high score. As in the Problem Solving section, time is of the utmost importance. Approaching Data Sufficiency

problems properly will help you use this time wisely.

Maths Concepts You Should Know

We began this chapter with a question. If that question were to be a DS question, what is needed is the ability to solve the

question if provided with sufficient time (with the help of basic concepts of mathematics). The solution is not the objective

but the ability to arrive at the solution is the objective. Our question is difficult (isnt it?) and will take considerable time for

solving such huge exponent values. Nevertheless, its solvable!

This type of question, which either appears in the Quantitative section or the Data Interpretation/Analytical Reasoning

section is designed to test your Quantitative Reasoning Ability. The data sufficiency questions cover the math areas that

nearly every college student will know. In addition to basic arithmetic, you can expect questions which will test your

knowledge of averages, fractions, decimals, algebra, factoring, and basic geometry such as triangles, circles, and areas and

volumes of simple geometric shapes and concepts of Modern Maths like Set Theory, Permutations and Combinations.

The data sufficiency problem consists of a question and two statements labeled (1) and (2), in which certain data are given.

You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given

in the statements plus your knowledge of mathematics and familiarity with everyday facts (such as the number of days in

July or the number of minutes in an hour, the meaning of counterclockwise), you must indicate whether

4 Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient to answer the question asked;

4 Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient to answer the question asked;

4 BOTH statements (1) and (2) TOGETHER are sufficient to answer the question asked, but NEITHER statement ALONE is

sufficient;

4 EACH statement ALONE is sufficient to answer the question asked;

4 Statements (1) and (2) TOGETHER are NOT sufficient to answer the question asked, and additional data specific to the

problem are needed.

Things you should never forget

4 Figures: A figure accompanying a data sufficiency problem will conform to the information given in the question, but will not

necessarily conform to the additional information given in statements (1) and (2).

4 Lines shown as straight can be assumed to be straight and lines that appear jagged can also be assumed to be straight.

4 You may assume that the positions of points, angles, regions, etc., exist in the order shown and that angle measures are

greater than zero.

Fundamentals of Data Sufficiency

Chapter 1 | Fundamentals of Data Sufficiency | BMM10236 | 2 of 40

4 All figures lie in a plane unless otherwise indicated.

4 Note: In data sufficiency problems that ask for the value of a quantity, the data given in the statements are sufficient only

when it is possible to determine exactly one numerical value for the quantity.

Example:

In triangle PQR, what is the value of x?

Statement 1: PQ = PR

Statement 2 : y = 40

Explanation: According to statement (1), PQ = PR; therefore, (PQR is isosceles and y = z. Since x + y + z = 180, it follows that

x + 2y = 180. Since statement (1) does not give a value for y, you cannot answer the question using statement (1) alone.

According to statement (2), y = 40; therefore, x + z = 140. Since statement (2) does not give a value for z, you cannot answer

the question using statement (2) alone. Using both statements together, since x + 2y = 180 and the value of y is given, you

can find the value of x. Therefore, BOTH statements (1) and (2) TOGETHER are sufficient to answer the question, but

NEITHER statement ALONE is sufficient.

Why to have a Test on Data Sufficiency

Negative reactions to Data Sufficiency questions are both common and understandable. This question type is exclusive to

the B-School exams, which means that anyone taking the CAT for the first time will never have seen it before. Unfamiliarity

breeds anxiety, which can lead to outright terror on test day. But with a little coaching and a lot of practice, test takers can

learn how to attack these problems and turn anxiety into confidence. At first glance, Data Sufficiency questions might not

look helpful when trying to assess B-School applicants. They dont even require you to calculate answers, so they dont test

your maths skills. The test makers obviously include these gratuitous questions simply to make peoples lives miserable,

right? Wrong. Data Sufficiency questions challenge a test takers thought processes and approach to problem solving. As

a leader in the business community, a manager with an MBA must have the ability to analyze a problem, figure out what

needs to be done, and delegate the task to the proper employees. The employees will do the work, but the manager needs to

assign the proper tasks.

This is the crux of what Data Sufficiency tests. For instance, to determine whether or not the company makes a profit, a

manager must know the total revenue and expenses, and then compare the two values. However, its up to the accounting

department to provide the manager with the totals for revenue and expenses. The manager knows what information is

needed, yet others gather it.

Most students initially have much more difficulty with the Data Sufficiency problems than with the Standard

Maths problems. However, the mathematical knowledge and skill required to solve Data Sufficiency problems are no greater

than that required to solve standard math problems. What makes Data Sufficiency problems appear harder at first is the

complicated directions. But once you become familiar with the directions, youll find these problems no harder than standard

maths problems. In fact, students usually become proficient more quickly on Data Sufficiency problems.

This Booklet is outlined into 4 parts:

I. Introduction (which we have already covered)

II. Strategies for Solving Data Sufficiency Questions (Chapter 2)

III. Data Sufficiency Trick Questions (Chapter 3)

IV. Practice questions

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