In this guide
Some DI sets have no logic to crack. The table is complete, the questions are clear, and the only obstacle is arithmetic: ten growth rates, five margins, a few shares. These sets are safe marks for a well-prepared aspirant and a time trap for everyone else, because the difference between the two is not calculation speed. It is knowing which calculations to skip.
This guide works through one realistic table and shows, question by question, how to get each answer with the least computation. All figures below are made up for practice, and every result has been re-computed.
The worked table
Revenue and profit of five companies, in ₹ crore (hypothetical figures).
| Company | Revenue 2024 | Revenue 2025 | Profit 2025 |
|---|---|---|---|
| Alpha | 480 | 552 | 69 |
| Beta | 625 | 700 | 77 |
| Gamma | 360 | 423 | 54 |
| Delta | 815 | 880 | 101 |
| Epsilon | 290 | 348 | 41 |
| Total | 2,570 | 2,903 | 342 |
Technique 1: growth rates by benchmark
Growth = increase ÷ old value. You rarely need the decimal; you need to know which is biggest, or roughly how big.
Q1. Which company had the highest revenue growth from 2024 to 2025?
| Company | Increase | Increase ÷ base | Benchmark reading |
|---|---|---|---|
| Alpha | 72 | 72/480 | 10% of 480 is 48, 5% is 24: exactly 15% |
| Beta | 75 | 75/625 | 625 × 0.12 = 75: exactly 12% |
| Gamma | 63 | 63/360 | 36 is 10%, 63 is 1.75 times that: 17.5% |
| Delta | 65 | 65/815 | 8% of 815 is 65.2: just under 8% |
| Epsilon | 58 | 58/290 | 58 is one-fifth of 290: 20% |
Answer: Epsilon, 20%. Notice that Epsilon had the smallest increase in crore and the highest growth. Small bases inflate percentages.
Technique 2: comparing two ratios by cross-multiplication
Q2. Which company had the highest profit margin (profit ÷ revenue) in 2025?
First, rough readings.
- Alpha: 69/552. 552 ÷ 8 = 69, so exactly 12.5%.
- Beta: 77/700 = 11%.
- Gamma: 54/423. 10% is 42.3, and 54 is about 1.28 times that: about 12.8%.
- Delta: 101/880. 10% is 88, 12.5% is 110: somewhere near 11.5%.
- Epsilon: 41/348. 10% is 34.8, 12.5% is 43.5: about 11.8%.
Alpha and Gamma are close. Cross-multiply to settle it: compare 54/423 with 69/552.
- 54 × 552 = 29,808.
- 69 × 423 = 29,187.
29,808 is larger, so 54/423 is larger. Answer: Gamma, about 12.77% against Alpha's 12.5%.
The rule: for a/b versus c/d (all positive), a/b is larger exactly when a × d is larger than c × b.
Technique 3: when approximation is safe
Approximation is safe when the options are far apart relative to your error. It is not safe when two candidates are within a percentage point, as Alpha and Gamma were.
A quick test: round each number by no more than 2%, and your answer moves by no more than about 4%. If the options differ by more than that, round freely.
Q3. By what percentage did the combined revenue of the five companies grow?
- Increase: 2,903 − 2,570 = 333.
- 333 ÷ 2,570: 10% is 257, leaving 76; 76 is about 3% of 2,570 (3% is 77.1).
- About 13% (12.96% exactly).
If the options were 11%, 13%, 15% and 17%, "a little under 13%" is enough. If they were 12.8%, 13.0% and 13.2%, you would need one more digit: 2,570 × 0.13 = 334.1, just above 333, so the answer is just below 13%.
Technique 4: shares and the base effect
Q4. What was Delta's share of combined revenue in 2025, and did it rise or fall from 2024?
- 2025: 880 ÷ 2,903. One-third of 2,903 is about 968, and 880 is below that. 30% is 870.9, so the share is just over 30% (30.3%).
- 2024: 815 ÷ 2,570. 30% is 771, 32% is 822.4, so it is just under 32% (31.7%).
- It fell. Delta grew under 8% while the total grew about 13%, and a part that grows slower than the whole always loses share.
That last sentence answers "did the share rise or fall" without dividing at all.
Q5 (TITA). If Beta's revenue grows in 2026 at the same rate as in 2025, what will it be, in ₹ crore? 700 × 1.12 = 784.
Q6. What was the combined profit margin of the five companies in 2025? 342 ÷ 2,903. 10% is 290.3, 12% is 348.4: about 11.8%. Note that this is not the average of the five margins; a combined margin weights each company by its revenue.
Deciding what to compute
| Question type | Usually enough | Compute exactly only if |
|---|---|---|
| Which is largest or smallest? | Benchmarks, then cross-multiply the top two | Two are within about 1% |
| Did it rise or fall? | Compare growth of part and whole | Never |
| Approximately what value? | One rounded division | Options are within 2% of each other |
| TITA value | Exact arithmetic | Always, with a check |
Common mistakes
- Dividing everything before reading the options. Read the options first; they tell you how precise you need to be.
- Averaging percentages. The combined margin (11.8%) is a weighted figure, not the mean of five margins.
- Confusing percentage points with percent. Delta's share fell by about 1.4 percentage points, which is a fall of about 4.4% of its old share.
- Rounding in the same direction every time. Round one number up and one down where you can, so the errors cancel.
Practice set
- From the table, which company had the lowest profit margin in 2025?
- By how many percentage points did Epsilon's share of combined revenue change from 2024 to 2025, to one decimal place?
- Which is larger, 47/83 or 53/91?
Answers:
- Beta, 11%. Delta (about 11.5%) and Epsilon (about 11.8%) are both above 11%: 11% of 880 is 96.8, below Delta's 101, and 11% of 348 is 38.3, below Epsilon's 41.
- Up 0.7 percentage points. 2024: 290 ÷ 2,570 ≈ 11.3%. 2025: 348 ÷ 2,903 ≈ 12.0%. Epsilon grew 20% against the total's 13%, so a rise was certain before dividing.
- 53/91. 47 × 91 = 4,277 and 53 × 83 = 4,399. The larger product belongs to 53/91.
What to do next
- Take one DI set a day this week and, before calculating, write the precision the options demand.
- Practise ten cross-multiplication comparisons; they should take under fifteen seconds each.
- Learn the fraction benchmarks in calculation speed for DILR.
- Apply the techniques to table-based DI and bar and line charts.
A note on dates and numbers. Exam patterns, vacancies and schedules change from year to year. Always confirm the current details in the latest notification on the Indian Institutes of Management website .
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