Negative marking and accuracy in IBPS Clerk

In both stages of IBPS Clerk, a wrong answer takes marks away. An unattempted question costs nothing. That one rule changes how you should attempt the paper, and most candidates only half understand it.

The good news is that the arithmetic is simple. Once you have done it once, you will know exactly when to guess, when to skip, and why a candidate who attempts fewer questions can finish ahead.

What a wrong answer costs in each section

In the prelims every question carries 1 mark, so the penalty is 0.25. In the mains, questions carry different marks, so the penalty differs too.

The mains figures follow the 2026 pattern as reported. See the exam pattern for how these are derived.

Two ways to feel the size of the penalty:

• Four wrong answers cancel one right answer. 4 × 0.25 = 1.
• A wrong answer is 1.25 marks worse than a right one on a 1-mark question, and 0.25 worse than skipping.

The arithmetic of guessing

IBPS questions usually have five options. Take a 1-mark question.

Blind guess, all five options still possible. The chance of being right is 1 in 5.

• Expected marks = (1/5 × 1) − (4/5 × 0.25) = 0.20 − 0.20 = 0.

On average, a blind guess gains nothing. It only adds risk. With five options and a one-fourth penalty, the expected gain and loss from a blind guess cancel exactly.

Now eliminate options and the picture changes.

Worked check for three options left: (1/3 × 1) − (2/3 × 0.25) = 0.333 − 0.167 = +0.17.

Worked check for two options left on a mains reasoning question: (1/2 × 1.5) − (1/2 × 0.375) = 0.75 − 0.1875 = +0.5625.

So the rule is: eliminate first, then guess. Ruling out one option makes a guess very slightly positive. Ruling out two makes it clearly worth taking.

Why accuracy beats attempts

Here is the same 35-question section attempted two ways. These are made-up figures to show the arithmetic.

B attempted five fewer questions and scored 3.75 more. Those eight wrong answers did double damage to A: they cost 2 marks in penalties, and the time spent on them could have gone into checking the questions that were right.

Worked example 2. A candidate attempts 28 prelims questions in a section, with 23 right and 5 wrong.

1. Penalty = 5 × 0.25 = 1.25.
2. Score = 23 − 1.25 = 21.75.
3. If those five had been skipped, the score would have been 23. The wrong answers cost 1.25 marks, plus the minutes spent on them.

Worked example 3. A mains reasoning section: 30 attempted, 25 right, 5 wrong, 1.5 marks each.

1. Marks for correct answers = 25 × 1.5 = 37.5.
2. Penalty = 5 × 0.375 = 1.875.
3. Score = 37.5 − 1.875 = 35.625.

Worked example 4. Is it better to attempt 30 at 80% accuracy or 26 at about 92%?

1. 30 at 80% means 24 right and 6 wrong: 24 − 1.5 = 22.5.
2. 26 with 24 right and 2 wrong: 24 − 0.5 = 23.5.

The slower, more accurate approach wins, and it also leaves time to double-check. Speed matters in this exam, but only speed that stays accurate.

Where wrong answers really come from

When you classify your mock errors, most fall into four groups. Each has its own fix.

Habits that raise accuracy

• Read the stem before the data in DI and puzzles, so you know what you are looking for.
• Check against the options. If your answer is not among them, the error is yours, not the paper's.
• Do not change an answer at the last minute without a clear new reason. First instincts backed by working are usually right.
• Mark and move. If a question needs one more minute, mark it for review and come back only if time is left in that section.
• Stop guessing when tired. In the last two minutes of a section, attempt only what you can actually solve.

An accuracy target

Aim for 90% or higher accuracy in each section of your mocks.

• Below about 80%: reduce attempts and slow down. You are losing marks to penalties and to rushing.
• Between 80% and 90%: find the one error type that repeats and fix it.
• Above 95% with low attempts: you are being too cautious or too slow. Push speed, especially on calculation.

Accuracy % = correct ÷ attempted × 100.

Practice

1. A prelims candidate attempts 32 questions and gets 27 right. Score?
2. In the mains awareness section, a candidate attempts 34 and gets 28 right. Score?
3. On a 1-mark question you can rule out two options. What is the expected gain from guessing?
4. How many wrong answers cancel one correct answer in the prelims?
5. Candidate X attempts 30 with 21 right. Candidate Y attempts 25 with 22 right. Who scores more?
6. What minimum chance of being right makes a guess worthwhile on a five-option question?

Answers:

1. 5 wrong: 27 − 1.25 = 25.75.
2. 6 wrong: 28 × 1.25 = 35; 6 × 0.3125 = 1.875; 35 − 1.875 = 33.125.
3. Three options left: 1/3 − (2/3 × 0.25) ≈ +0.17 marks.
4. Four, because 4 × 0.25 = 1.
5. X: 21 − (9 × 0.25) = 18.75. Y: 22 − (3 × 0.25) = 21.25. Y scores 2.5 more.
6. More than 20%, which is exactly the blind-guess chance with five options.

What to do next

• Add a "wrong" column and an accuracy column to your mock log.
• For the next three mocks, classify every wrong answer into one of the four causes above.
• Set a rule for yourself: no guess unless two options are ruled out.
• Read the mock test guide for the full analysis method, and the common mistakes list.