Data Interpretation questions check you're analyzing and calculation skills. The key to solving DI questions is to identify the important values, convert all the data into important information related to which Questions are asked. Remembering tables, squares, cubes, etc. will help you in improving the calculations. Shortcut tricks, direct formulas, Vedic maths can be helpful in increasing the speed of calculation. Try to do calculations in mind. It can be a better strategy to save time. The best way to calculate in mind is by using the approximate values for the given data.
Let`s now discuss the Pie Chart in detail.
Pie Chart is a circular form of Data representation. In this, the circle is divided into sectors either per cent-wise or degree-wise. In the per cent-wise division, the total area of the chart is taken to be 100% and in the degree-wise division, the total area of the chart is taken to be 360o.
Directions: Study the following pie chart and answer the questions that follow:
Total Number of Teachers = 6400
(Uttar Bihar Gramin Bank 2012)
Question 1: If one-thirty-sixth of the number of teachers from university F is professors and the salary of each professor is Rs 96000, what will be the total salary of all the professors together from university F?
 Rs. 307.2 lakh
 Rs. 32.64 lakh
 Rs. 3.072 lakh
 Rs. 3.264 lakh
 None of these
Number of teachers from university F = 18% of 6400 = 1152
1/36 of 1152 = 32
Total salary = 32*96000 = 3072000 = 30.72 lakh. Answer  is correct. (Note the tricky options  and )
Question 2: Difference between the total number of teachers in universities A, B, and C together and the total number of teachers in universities D, E, and F together is exactly equal to the number of teachers in which university?
(You don’t even have to calculate the number of teachers. Just presence of mind is needed.)
Number of teachers in university A, B and C = 11+17+19 = 47%
Number of teachers in university D, E and F = 6+29+18 = 53%
Difference = 6% = University D. Answer  is correct.
Question 3: What is the average of teachers in universities A, C, D, and F together?
 None of these
Again, solving it quickly.
11+19+6+18 = 54%. Average = 54/4 % = [54/400]*6400 = 54*16 = 864.
Answer  is correct.
Question 4: If twenty-five percent of the number of teachers in university C is female, what is the number of male teachers in university C?
 None of these
Number of teachers in university C = 19% of 6400 = 19*64 = 1216
25% of this is female. Hence remaining 75% is male.
Number of male teachers = 75% of 1216 = [3/4]*1216 = 912. Option  is correct.
Question 5: The number of teachers in University B is approximately what percent of the total number of teachers in university D and E together?
Just solve the percentages.
University B = 17%. University D+E = 6+29 = 35%
Required percentage = [17/35]*100 = approx. 49%. Answer is 
- Practice is the only way to increase your attempts in the exam and it will also help you improve your speed as well as calculation skills.
- Try to attempt a lot of sets of Data Interpretation to analyze your preparation level.