A quant and DI plan for SBI PO

In the SBI PO mains, the quant section is called Data Analysis & Interpretation, and the name is accurate. Most questions sit on a table, a chart or a paragraph of data, and each one is worth two marks. In the prelims, quant is a 30-question, 20-minute section that mixes quick calculation types with DI and arithmetic.

So every arithmetic chapter you study is really DI practice in disguise. This guide shows how to plan for that, which shortcuts matter most and why they work, and gives worked questions and a practice set at exam level.

How quant appears in each phase

The mix of question types varies from year to year, so treat the last row as a guide to what has appeared, not a promise.

Topic priorities

Six shortcuts, and why they work

1. Know fractions as percentages. 1/6 = 16.67%, 1/7 ≈ 14.29%, 1/8 = 12.5%, 1/9 ≈ 11.11%, 1/11 ≈ 9.09%, 1/12 ≈ 8.33%. Most DI answers are ratios, and recognising 115/890 as "a little over 1/8" saves a long division.

2. Successive percentage change: a + b + ab/100. A rise of a% followed by a change of b% multiplies the value by (1 + a/100)(1 + b/100) = 1 + (a + b)/100 + ab/10,000. The last term is the ab/100 in percentage form. Use a minus sign for a fall.

3. Undoing a change. If a value rises by r%, it must fall by r/(100 + r) × 100% to return. A 25% rise needs a 20% fall, because the fall is taken on the larger base of 125.

4. CI minus SI for two years = P × (r/100)². Compound interest earns interest on the first year's interest. That extra is (P × r/100) × r/100.

5. Chain ratios through the common term. If A:B = 3:5 and B:C = 4:7, make B the same in both (20): A:B:C = 12:20:35.

6. Average change. When a new value joins a set, new value = new average + (number of old values × rise in average). It comes from new total minus old total.

Worked questions

Questions 2 to 4 use this table.

Question 1. A fee is raised by 20% and then cut by 15%. What is the net change?

• a + b + ab/100 = 20 − 15 + (20 × −15)/100 = 5 − 3 = +2%.

Question 2. Which branch had the highest percentage growth from 2024 to 2025?

• P: 60/240 = 25%. Q: 27/180 = 15%. R: −32/320 = −10%. S: 60/150 = 40%.
• S, at 40%. Note that P and S grew by the same amount (₹60 crore), but S from a smaller base.

Question 3. By what percentage did total deposits rise?

• Rise = 1,005 − 890 = 115. Percentage = 115/890 × 100.
• 1/8 of 890 is 111.25, which is 12.5%. The remaining 3.75 is about 0.42% of 890.
• About 12.9%.

Question 4. What is the ratio of R's 2025 deposits to Q's 2024 deposits?

• 288 : 180. Divide both by 36: 8 : 5.

Question 5. What is the difference between compound and simple interest on ₹8,000 at 10% a year for two years?

• 8,000 × (10/100)² = 8,000 × 0.01 = ₹80.
• Check: SI = 1,600. CI = 8,000 × 1.21 − 8,000 = 1,680. Difference 80.

Question 6. An aspirant's average over five mocks is 62. After the sixth mock the average is 64. What did they score in the sixth?

• New total 6 × 64 = 384. Old total 5 × 62 = 310. Sixth mock = 74.
• Shortcut: 64 + 5 × 2 = 74.

An eight-week order

From week 3, end every arithmetic session with one DI set that uses that topic.

Daily drills (20 minutes)

• Ten simplification or approximation questions, timed.
• Five percentage-of-number calculations in your head.
• One DI set of five questions, timed at about six minutes.

Track the time for the last block. It is the best single measure of whether your quant is improving.

Choosing DI sets in the exam

1. Scan all sets for about a minute.
2. Start with the set whose numbers look cleanest and whose questions look direct.
3. Leave a caselet with many conditions for later.
4. If a set turns out to be calculation-heavy after two questions, move on.

Practice set

1. A value rises by 25% and then falls by 20%. What is the net change?
2. Using the table, by what percentage did R's deposits fall?
3. What was the average deposit per branch in 2024?
4. Find the difference between CI and SI on ₹12,500 at 8% a year for two years.
5. What is 37.5% of 1,344?
6. Roughly what percentage of total 2025 deposits did S hold?
7. A:B = 3:5 and B:C = 4:7. Find A:B:C.
8. If Q's deposits grow at the same rate in 2026 as in 2025, what will they be?

Answers:

1. 0%. 25 − 20 + (25 × −20)/100 = 5 − 5 = 0.
2. 10%. 32/320.
3. ₹222.5 crore. 890 ÷ 4.
4. ₹80. 12,500 × (8/100)² = 12,500 × 0.0064.
5. 504. 37.5% = 3/8; 1,344 ÷ 8 = 168; 168 × 3 = 504.
6. About 21%. 210/1,005 ≈ 0.209.
7. 12 : 20 : 35. Make B = 20 in both ratios.
8. ₹238.05 crore. Growth was 27/180 = 15%; 207 × 1.15 = 238.05.

What to do next

• Learn the fraction–percentage table this week until you can recall it without thinking.
• Start the daily 20-minute drill and log your DI time.
• Work through simplification and approximation and number series for the prelims.
• Move to tabular DI by week 5.