In recent years, some of the questions in this section have become tougher, and so some students fear this section. What must be remembered is that, like other sections as well, if you make sure that you are familiar with the type of questions that you get and the possible methods of solution, you should be able to manage a decent score, especially if you work hard and in the right direction.

Hence, let us look at the various categories of questions that you could get. Most Data Interpretation sections would have any or all the following categories:

Tables
Tables refer to the arrangement of data in the form of rows and columns. The row and/ or column totals may be provided to you, else you may have to calculate these if the question requires you to. Keep in mind that very often, approximations may be sufficient for these row or column totals rather than spending time actually calculating the exact values.

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An important thing is that you should pay careful attention to details in the table like units of measurement etc -- do not start comparing different quantities having different units! Similarly, make sure you notice any additional information provided in notes and marked with an asterisk in the data-this might indicate some specialty or difference in that particular category or incomplete data etc.

Therefore, it is suggested that you keep in mind the following important points while attacking these questions:

• First glance through the available data, trying to take in the captions, notes, units etc.
• Try to make approximations to save time whenever appropriate, rather than spend time on find exact numbers. Approximations coupled with a proper understanding of what the question asks you to calculate can certainly help in eliminating options and narrowing down your possible answer choices. 
• The answer you calculate might have a different unit as compared to the units of the answer choices. In this case, you will have to convert into the appropriate unit. For example, a variable such as population may be given in millions in the data provided to you, while the answer choices may express population in crores, thus requiring you to make the necessary conversion.

Graphs
While tables express actual numbers, graphs are a diagrammatic representation of data. They bring out the relationship between data more clearly than numbers in a table. For example, using a pie-chart can bring out clearly the percentage that Anil Ambani [Images] owns of Reliance Communications Ltd [Get Quote] and the fact that he is the largest shareholder, while a table would require you to actually calculate the percentage of each shareholder's ownership to find out the largest shareholder.

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Graphs are far better to understand changes in variables-whether a particular value has risen or fallen over the past few years and hence trend lines etc. Remember that in graphs, actual values may not be given (for example, only percentages and the total may be given in a pie-chart), hence the question may require you to find the actual value before making a comparison. Thus a common thing that you might have to do for questions pertaining to bar graphs is to trace a line to the appropriate axis to determine the actual value (or approximate it).

You will also find questions pertaining to line graphs. These show relationships between variables and data as well as trends like growth and decline over a period of time. Such graphs are most often used for time series data and frequency distributions.

Pie Charts derive their name from its shape, like that of a pie divided into various portions. They always represent data in the form of a percentage of the total, with the total percentage being 100. In such a chart, the length of the arc (and therefore the angle each sector subtends at the centre) is proportional to the quantity it represents. Such charts are often used in the corporate world and in newspapers. Since a circle comprises 360 degrees, each percent of a pie-chart is equal to 360 divided by 100, or 3.6 degrees. This fact will be important for the calculations you are expected to perform.

Caselets
Caselets are basically a set of linked questions -- there are two to five questions based on the same information and the questions are related in some manner. Very often, caselets provide data within a paragraph or a set of statements, rather than in the form of a table or graph. Thus the solution to the caselet often lies in making the correct table for the data. There will be missing numbers in the table, and hence you will have to consider various possibilities for the possible values of these missing numbers.

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Preparing the table can be time consuming and effort intensive. Hence, is strongly advised that you practice a lot and very regularly for these kind of questions. Also, remember that since there are 3-4 questions based on the same statements, solving such sets can be extremely rewarding.

Data Sufficiency
In such questions, you are given a question statement followed by two further statements. You have to determine whether the answer can be found by:

1) Using one of the statements alone, while the other statement is not sufficient to answer the question.
2) Using each of the statements independently.
3) If both the statements together are needed to answer the question and it cannot be answered by any one of the statements alone  
4) Or if both the statements taken individually or together are still insufficient to answer the question

The Data Interpretation and Analytical Reasoning section in CAT and other management school entrance examinations can have various types of tables, graphs, caselets, puzzles etc. The key to doing well in this section is understanding the various types of diagrams or analysing the caselet properly. The more your familiarity with various types of questions or figures that can come, the better your chance of doing well, for you will understand the kind of questions that are usually associated with a particular kind of graph or table. 

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The author is an MBA from IIM Calcutta and is employed with a management consultancy. He is also a visiting faculty with MBA coaching centres in New Delhi [Images] and a freelance writer on travel and management related issues.

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