Data interpretation for IBPS Clerk

Data interpretation (DI) gives you a table or a chart and a group of questions on it, usually five. In the clerk exam the arithmetic is rarely hard. What costs marks is reading the wrong row, missing a unit, or computing a full percentage when the options were far enough apart to estimate.

DI is the one place in the numerical section where time invested pays out in bulk. You read the data once and then collect several answers from it. That is why the numerical ability plan budgets four to five minutes for one set in the prelims, and why the mains leans on DI more heavily.

The four chart types

A pie chart given in percentages with a total is really a table in disguise. Each slice is total × percentage ÷ 100. Once you see that, most pie questions become one multiplication.

The five calculations behind almost every question

• Total or sum: add the relevant cells. Add in pairs that make round numbers.
• Average: total ÷ count. If the options are close, compute the total exactly.
• Ratio: write both values and cancel. 360 : 840 → divide by 120 → 3 : 7.
• Percentage change: (new − old) ÷ old × 100. The base is always the earlier value.
• Percentage share: part ÷ whole × 100. The base is the whole named in the question.

Most wrong answers in DI come from the wrong base. "What percent of the 2025 total" and "what percent more than 2024" use different denominators, and the examiner puts both results among the options.

Shortcuts, and why they work

Turn divisions into known fractions. 40 ÷ 320 is 1/8, which you know is 12.5%. It works because a percentage is only a fraction scaled by 100, so any fraction you have memorised is a percentage you already know.

Compare percentage changes without computing them. To find the branch with the highest growth, compare increase ÷ base as fractions. 40/160 = 1/4 beats 50/250 = 1/5 at a glance. You are comparing the same quantity the formula gives, just before multiplying by 100, which changes nothing about the order.

Estimate when options are spread out. If the options are 7%, 12%, 18% and 25%, then 100 ÷ 1,400 is clearly about 7%. Exact work is needed only when two options sit close together.

Write the column totals once. If a set asks about totals twice, calculate them at the start and note them beside the table.

A worked set

The table shows the number of new savings accounts opened by five branches of a bank in two years. It is a made-up set for practice.

Before the first question, write the column totals: 2024 = 1,400 and 2025 = 1,500.

Q1. By what percentage did accounts at branch P increase from 2024 to 2025?

1. Increase = 300 − 250 = 50.
2. 50 ÷ 250 = 1/5 = 20%.

Q2. What was the average number of accounts per branch in 2025?

1. The total is already noted: 1,500.
2. 1,500 ÷ 5 = 300.

Q3. What is the ratio of branch R's accounts over both years to branch S's accounts over both years?

1. R: 160 + 200 = 360. S: 400 + 440 = 840.
2. 360 : 840. Divide both by 120 → 3 : 7.

Q4. Which branch had the highest percentage increase from 2024 to 2025?

1. Q fell, so drop it. Write increase/base for the rest: P 50/250 = 1/5, R 40/160 = 1/4, S 40/400 = 1/10, T 10/270, which is under 4%.
2. 1/4 is the largest fraction, so the answer is R (25%).

Q5. By what percentage did the total number of accounts rise from 2024 to 2025?

1. Increase = 1,500 − 1,400 = 100.
2. 100 ÷ 1,400 = 1/14 ≈ 7.14%.
3. Note that this is not the average of the five branch percentages. Totals must be compared as totals.

Common mistakes

• Using the new value as the base for percentage change.
• Missing the unit line ("figures in thousands") and choosing an option that is off by a factor of 1,000.
• In pie charts, taking the percentage of the wrong total when two pies are given.
• Starting the heaviest set first. Scan every set for 10 seconds and begin with the one with the friendliest numbers.
• Averaging percentages instead of working from totals.

Speed routine for one set

1. Read the title, headings and units. Ten seconds.
2. Glance at all five questions and note which totals they need.
3. Compute those totals once.
4. Answer the easy questions first: direct reads and ratios.
5. For percentage questions, look at the options before calculating fully.

If a set still looks calculation-heavy after step 2, move on. You can come back with the time you save elsewhere.

Practice set

The pie chart below, written as a table, shows how 2,400 loans sanctioned by a bank in one year were split by type. It is made-up data.

Set a 5-minute timer.

1. How many personal loans were sanctioned?
2. How many more home loans than education loans were sanctioned?
3. What is the ratio of vehicle loans to gold loans?
4. What is the central angle of the education slice in the pie chart?
5. If vehicle loans rise by 25% next year, how many vehicle loans will there be?
6. By what percentage are education loans fewer than vehicle loans?
7. What is the average of the number of home loans and personal loans?
8. By what percentage are personal loans more than home loans?

Answers:

1. 720. 30% of 2,400 = 3 × 240.
2. 240. The gap is 25% − 15% = 10%, and 10% of 2,400 = 240. Working with the percentage gap saves two multiplications.
3. 2 : 1. 20% : 10%. The total cancels, so you need no numbers at all.
4. 54°. 15% of 360° = 0.15 × 360.
5. 600. Vehicle loans = 20% of 2,400 = 480; 480 × 1.25 = 600.
6. 25%. (20 − 15) ÷ 20 × 100. The base is the vehicle figure, because the comparison is "fewer than vehicle".
7. 660. Home 600, personal 720; (600 + 720) ÷ 2.
8. 20%. (30 − 25) ÷ 25 × 100. The base is the home figure.

What to do next

• Learn the fraction–percentage pairs from 1/2 to 1/12 until you recall them without thinking.
• Do one timed DI set daily for two weeks, rotating table, bar, line and pie.
• After each set, write down which question used the wrong base, if any.
• Revise percentage and ratio and proportion, since every DI question is one or the other.
• Keep approximation sharp so you can estimate when options are spread out.