DI is speed arithmetic on a table. Read the question first, then only the cells it needs; approximate with the fraction table.
A chart is a question you answer by reading carefully. Half the marks in DI are lost by reading the wrong year, the wrong unit or the wrong bar.
DI sets carry 4 or 5 questions on one table or chart, so one set is worth a lot of marks. The maths is percentages, ratios and averages; the skill is reading.
Read the title, the units (thousands? lakhs? %?), the axes and the legend before the first question.
Then approximate: DI options are usually far enough apart that rounding to 2 significant figures is enough.
From the chart: by what percent did sales grow from 2021 to 2024?
Answer: 50%
Average sales over the four years?
Answer: 146.25
A pie chart shows shares of a whole. Sector angle = share × 360. A 90 degree sector is a quarter.
To get the actual value: share % × total.
If the family earns Rs 60,000 a month, how much more is spent on rent than on travel?
Answer: 9000
What is the angle of the Food sector?
Answer: 90
For a table, circle the row and column you need before calculating. For a line chart, the steepest segment is the biggest change, and a fall shows a line going down.
Ratios across years: compare using fractions of the same base, not by computing each value.
Use it when: Old 120, new 150.
120 → 150
Answer: 25%
Same table: overall % growth from 2024 to 2025 (2 d.p.)?
Answer: 11.86%
Same sales table: company B's share of total 2025 sales (2 d.p.)?
Answer: 26.82%
Production (thousand units) 2021-2025: 40, 50, 45, 60, 72. Which year had the highest % growth over the year before?
Answer: 2024
8 questions with full solutions.