Data Interpretation
About 7 min · Numerical and Mathematical Ability · English
Time worked out from the lesson's 524 words at 150 words a minute, plus a minute for each question.
Data Interpretation (DI) in SSC MTS Session-I tests your ability to read, understand and perform calculations on data presented in visual formats. The exam focuses on tables, bar graphs and pie charts with straightforward calculations — no complex multi-step reasoning or advanced statistics.
Key ideas
- Data formats: Tables present data in rows and columns with clear labels. Bar graphs show comparisons using horizontal or vertical bars scaled against an axis. Pie charts display parts of a whole as angular sectors, with total = 360° or 100%.
- Direct reading: Many questions simply ask you to read a value from the chart or find the difference/sum of two values. Always read axis labels, units and legends carefully.
- Percentage calculations: Most questions involve finding percentage increase/decrease, percentage share, or converting percentages to actual values. Remember: Percentage = (Part/Whole) × 100.
- Ratio and proportion: Questions often ask for the ratio between two categories or to find a value using proportional relationships from the data.
- Averages: Calculate the average of values across multiple categories or time periods. Average = Sum of all values / Number of values.
Watch out for
- Reading wrong row/column: Students often pick data from an adjacent row or column in tables. → Always trace with your finger and double-check the label before extracting a number.
- Missing the scale: Bar graphs often have axes labeled "in thousands" or "in lakhs". Students calculate with the bar height directly. → Always multiply by the scale factor mentioned on the axis label.
- Percentage of wrong base: When calculating percentage increase, students use the new value as base instead of old. → Remember: % change always uses the original/old value as the denominator.
Quick reference
- Tables: Read carefully, trace correct row/column, watch units.
- Bar graphs: Value = bar height × scale; check axis labels for "in thousands" etc.
- Pie charts: Percentage = Angle/360 × 100; Value = Angle/360 × Total or Percentage/100 × Total.
- Percentage change: (Change/Original) × 100; always use original as base.
- Average = Sum / Count; Ratio a:b with total T → parts are a/(a+b) × T and b/(a+b) × T.
Check yourself: 3 questions
1. The table below shows the number of students enrolled in five different courses at a coaching center. Course | Number of Students --- | --- Mathematics | 120 English | 150 Reasoning | 180 General Awareness | 90 Computer | 60 What is the total number of students enrolled in all courses combined?
2. A pie chart shows the distribution of monthly expenses of a family. The family spends 25% on rent, 30% on food, 15% on education, 20% on transport, and 10% on miscellaneous items. If the total monthly expense is Rs 24,000, how much does the family spend on food and transport together?
3. The bar graph below shows the production of rice (in thousand tonnes) by five states in a year. State | Production (thousand tonnes) --- | --- Punjab | 250 Haryana | 180 Uttar Pradesh | 320 West Bengal | 280 Andhra Pradesh | 200 What is the average production of rice by these five states?
This lesson is cut from the topic's note, not rewritten. Fact-checked on 21 Oct 2026: an AI-assisted check of this note against cited sources; the errors it found were corrected that day. Some errors may remain. The questions are from Shishya's validated question bank.
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