The usual penalty
Across SBI and IBPS objective papers, a wrong answer typically costs one-fourth of the mark allotted to that question, while an unattempted question costs nothing. So on a one-mark question, a correct answer is +1, a blank is 0, and a wrong answer is -0.25.
This fraction is a long-standing convention, not a guarantee. Some tests or sections have used different values, and the descriptive paper is marked differently. Always take the exact penalty from the current notification.
The maths of a guess
With a penalty of one-fourth on a question with five options, a pure blind guess has an expected value of zero: on average, 1 in 5 guesses is right (+1) and 4 in 5 are wrong (4 times -0.25 = -1), which cancels out. Blind guessing neither helps nor hurts on average, but it adds variance - it can swing a borderline result either way.
The picture changes once you can eliminate options:
- Eliminate 1 option (4 left): a guess now averages slightly positive.
- Eliminate 2 options (3 left): clearly positive - worth taking.
- Eliminate 3 options (2 left): strongly positive - take it.
So the rule of thumb is: guess only when you have removed at least two options; otherwise leave it blank.
Why a low wrong-answer count matters
Every wrong answer is a double loss: you forgo the mark you could have earned by spending that time on a question you knew, and you pay the penalty on top. Four careless wrong answers wipe out a fifth correct one.
Because selection is decided by small margins and by sectional cut-offs, a candidate who attempts fewer questions at high accuracy often outscores one who attempts more with a scatter of errors. Controlling negatives is usually more productive than chasing a few extra attempts.
Habits that reduce avoidable negatives
- Read the full question and all options before marking - many negatives come from missing a "not", "except" or "cannot".
- Mark as you go only when sure; flag doubtful ones and return, rather than committing under time pressure.
- Do a units-and-sign check on quantitative answers before moving on.
- Avoid last-minute panic filling. In the final minute, resist the urge to guess a block of unread questions.
- Track your accuracy in every mock, not just your attempts. If accuracy drops below the high-eighties in a section, you are attempting too many marginal questions.
Worked example: three candidates
One-mark questions, penalty one-fourth. Three candidates take the same 100-question section.
Candidate A attempts 70: 60 correct, 10 wrong. Score = 60 minus 10 times 0.25, that is 60 minus 2.5, which is 57.5.
Candidate B attempts 55: 52 correct, 3 wrong. Score = 52 minus 3 times 0.25, that is 52 minus 0.75, which is 51.25.
Candidate C attempts 62: 58 correct, 4 wrong. Score = 58 minus 4 times 0.25, that is 58 minus 1, which is 57.
Candidate A wins here, but only because their accuracy (60 of 70, about 86 percent) stayed high. Had A instead gone 55 correct and 15 wrong from the same 70 attempts, the score would be 55 minus 3.75, that is 51.25 - the same as the cautious Candidate B, from far riskier play.
Common mistakes
- Blind guessing to "use up" the paper. With five options and a one-fourth penalty, that averages to zero and only adds risk.
- Guessing after eliminating just one option. The edge is tiny; wait until two are gone.
- Treating a blank as a failure. A blank is a neutral, deliberate choice; a wrong answer is a loss.
- Ignoring "except" and "not" in the stem. These reversed questions cause a large share of avoidable negatives.
- Measuring only attempts in mock analysis. Accuracy per section is the number that predicts your real score.
- Assuming the penalty is always one-fourth. Confirm it from the current notification for your exam.
Quick revision
- Usual penalty: minus one-fourth of the question's mark for a wrong answer; zero for a blank. Confirm from the notification.
- Five options, one-fourth penalty: a blind guess averages zero and only adds variance.
- Guess only after eliminating at least two options; then the expected value is clearly positive.
- A wrong answer is a double loss - the mark not earned plus the penalty. Four wrongs cancel one right.
- Fewer attempts at high accuracy usually beat more attempts with scattered errors, given sectional cut-offs.
- Reduce negatives by reading the full stem (watch "not"/"except"), flagging doubtful items, checking units and signs, and never panic-filling.
- Track accuracy per section in every mock, not just the attempt count.