November 7, 2012

How to prepare for DI

Video 1 Ten DI Myth busters

Video 2 How to solve DI without pen

Visual DI

Why this Kolaveri , D.I. ?

The CAT Quant section includes between two and four Data Interpretation sets which will always include a graph, chart, or data table. If you aren’t already a numbers fan, this section can be very intimidating. Data Interpretation questions are like an open-book test. You have the questions in front of you as also the answers. All D.I. asks of you is an eye for detail and quick calculations. Below are some tips to help you breeze through this section.

  • Before attempting D.I. you should be thorough with the reciprocals up to 20 (For ex- 1/3 = 33.33%,…,1/6 = 16.67%,….,1/8 = 12.5%,….,1/20 = 5%). There always are 1-2 questions on increase of quantity A over B, etc. The reciprocals would be immensely helpful here. Also remember doubling the value of variable is equivalent to an increase of 100 per cent, tripling is equivalent to an increase of 200 per cent and so on. Likewise increase of 350% is equivalent to 4.5 times the number, 475 is 5.75 times. Lastly, A% of B = B% of A i.e. 97.6% of 25 is simply one-fourth of 97.6


  • Make sure you read every tiny piece of writing on or near the data, including titles, the labels for the x and y-axes, column names, and even footnotes. Scroll down to make sure you’ve caught everything.  Mentally categorize each graph, chart and table. (EX: “This is a graph showing the change in the price of onions per kg over the course of one year.”) Do not just skip the statistics entirely and go straight to the question! While you may think this will save you time, it actually significantly decreases your accuracy.


  • Once you understand the labels, take special care to note the units (mph, m/sec, cm2, etc.). Never ignore the units given for the variables. Are we dealing with seconds, minutes, or hours? Does one graph represent the month of June, while the other graph represents the entire year? The units may change from graph-to-graph or chart-to-table. Especially note any given information about percentages, as DI questions frequently require you to work with percents and raw numbers. Sometimes the answer choices are arranged in such a way that there is always a strong possibility to pick up the wrong one if one does not consider units.


  • Be very careful to read the data from the right spot. In gleaning data from a chart, graph or table, it’s remarkably easy to inadvertently grab your data from the wrong graph, bar, line, etc. This is the #1 cause of incorrect responses in CAT Data Interpretation. To avoid this blunder, point your finger to the data you want; put your finger directly against the question and keep it there until you’re sure you’re looking at the right part of the right chart or graph. Better to read twice, calculate once. Most mistakes are made not in the calculation, but in using the wrong data. Don’t rush.


  • Instead of wasting time in doing lengthy calculations, you must try to solve the questions using approximations. Check to see if the question asks for an approximation. If so, you can safely estimate numbers by rounding off. A word of cautionWhen rounding off fractions, round the numerator and denominator in the same direction (either up or down); otherwise you’ll distort the value of the fraction. Don’t confuse percentages with raw numbers. Always ask yourself which type of number the chart or graph is providing, and which type the question is asking for.


  • Look for trends in the data. Quickly note the relationship between the variables in each table, chart, or graph. Do they have a direct or indirect correlation? Where does the data spike or significantly decrease?


  • It’s okay to rely on visual approximations when it comes to reading bar graphs and line charts. The test-makers are not out to test your eyesight. So if two or more answer choices come very, very close to your solution, rest assured that you needn’t estimate values more precisely. Instead, go back to square 1; you’ve made some other mistake along the way.



There is no such thing as a difficult DI question. What it probably means that you are expected to find out the answer from more than one statistic. These questions require multistep solutions. With the help of aforementioned tips and enough practice on your part, you can easily avoid any and all the kolaveris over DI!