Data interpretation gives you a table or chart and asks several questions from it. The numbers are easy; the time pressure is real. Read the title, the units, and the row/column labels first — half the wrong answers come from misreading what a number represents.
The two phrases that trip students
"% growth" = (new − old)/old × 100. "By how much" = absolute difference.| Year | Company A sales (Rs lakh) | Company B sales (Rs lakh) |
|---|---|---|
| 2021 | 200 | 150 |
| 2022 | 250 | 200 |
| 2023 | 300 | 280 |
How to Approach It
- **Read the frame first** — note the title, units and what each row and column represents before looking at a value. A misread unit quietly invalidates every answer that follows.
- **Classify the question** — 'percent growth' divides by the base; 'how much more' simply subtracts. Decide which is asked before you compute.
- **Estimate to eliminate** — round aggressively and discard options that are obviously too large or too small. You rarely need exact decimals to land on the right choice.
- **Keep each set self-contained** — never carry a figure from one data set into the next; re-anchor your reading to the new chart each time.
Techniques & Methods
- **Labels before numbers** — read the title, units and row/column headers first. e.g. 'Sales in lakh' vs 'units sold' changes the whole reading.
- **Relative vs absolute** — 'growth / % more' → divide by base; 'how much more' → subtract. e.g. 200 → 300 is +50%, or +100 in absolute terms.
- **Estimate to eliminate** — round and discard far-off options instead of dividing precisely. e.g. 51.7% ≈ 'about half' → pick 52% over 48%.
- **Self-contained sets** — never carry a number from one DI set into the next.
The Edge
Don't divide when you can compare. For "which year had the highest combined sales" just add and eyeball — no percentages needed. Round aggressively while scanning options. If choices are 33%, 40%, 50%, you rarely need decimals to pick the right one.Worked example
By what percent did Company A's sales grow from 2021 to 2023?
- 'Growth' is a relative change, so the formula is (new − old) ÷ old × 100, taking the earlier year as the base.
- From the table, A's sales were 200 in 2021 and 300 in 2023.
- Change = 300 − 200 = 100, and the base is 200.
- Growth = 100/200 × 100 = 50%.
Answer: Growth = 50%
Worked example
In 2022, Company A's sales were what percent more than Company B's?
- 'How much more, in percent' compares the two using the other company — here B — as the base.
- In 2022, A = 250 and B = 200.
- Difference = 250 − 200 = 50; the base is B = 200.
- So A is 50/200 × 100 = 25% more than B.
Answer: 25% more
Worked Drills
Worked example
(Use the revenue table: Product X & Y in Rs cr — 2022: X=120, Y=80; 2023: X=150, Y=120.) The total revenue in 2023 is:
- Add the two products for 2023.
- 150 + 120 = 270.
Answer: c) Rs 270 cr
Worked example
Product X's percent growth from 2022 to 2023 is:
- Growth = (new − old)/old × 100 = (150 − 120)/120 × 100.
- = 30/120 × 100 = 25%.
Answer: b) 25%
Worked example
Product Y's percent growth from 2022 to 2023 is:
- Growth = (120 − 80)/80 × 100.
- = 40/80 × 100 = 50%.
Answer: b) 50%
Worked example
In 2023, Product X's revenue is approximately what percent of the total?
- X = 150, total = 270.
- 150/270 × 100 ≈ 55.5%.
Answer: b) 55.5%
Worked example
The ratio of X to Y revenue in 2022 is:
- X = 120, Y = 80.
- 120 : 80 = 3 : 2.
Answer: a) 3:2
Worked example
The combined revenue grew from 2022 to 2023 by:
- 2022 total = 120 + 80 = 200; 2023 total = 270.
- Growth = (270 − 200)/200 × 100 = 35%.
Answer: b) 35%
Worked example
Company A's total sales over the three years (main table):
- Add A's three years: 200 + 250 + 300.
- = 750.
Answer: b) Rs 750 lakh
Worked example
Company B's percent growth from 2022 to 2023 (main table):
- B: 200 in 2022, 280 in 2023.
- (280 − 200)/200 × 100 = 40%.
Answer: b) 40%
Worked example
Across 2021-2023, total combined sales of A and B (main table):
- A total = 750, B total = 150 + 200 + 280 = 630.
- 750 + 630 = 1380.
Answer: c) Rs 1380 lakh
Worked example
Company A's 2022 sales are what percent of its 2023 sales, approx (main table)?
- A: 250 in 2022, 300 in 2023.
- 250/300 ≈ 83.3%.
Answer: c) 83%
⚠ Watch out
- "More than" uses the other value as the base, not the total.
- Check the unit — lakh vs crore vs raw count changes nothing in ratio questions but everything in "how much" questions.
- Don't carry data from one DI set into the next; each set is self-contained.
Takeaways
- Read the title, units and labels before any number — most errors are misreadings, not miscalculations.
- Separate 'percent growth' (divide by base) from 'how much more' (subtract).
- Round and eliminate; exact decimals are rarely needed to pick the option.
- Treat every dataset as self-contained — never carry a figure across sets.