Short answer: in RAS Prelims each question is worth 1.33 marks and a wrong answer costs 0.44 (one-third). A blind guess between four options gains nothing on average, while a guess between two options gains about 0.44 marks. So you reduce negative marking not by attempting fewer questions but by guessing only after elimination and by fixing careless errors. Those usually cost more marks than genuine gaps in knowledge.
The maths of a guess
These are expected marks per question, on the official scale of 200 marks for 150 questions with one-third negative marking (see the exam pattern):
| Your situation | Chance of being right | Expected marks |
|---|---|---|
| No idea, four options left | 25% | 0.00 |
| One option ruled out, three left | 33% | +0.15 |
| Two options ruled out, two left | 50% | +0.44 |
| Sure of the answer | about 100% | +1.33 |
Two practical rules follow:
- Never guess from zero. On average it gains nothing and it adds risk.
- Guess when you are down to two. The average gain is real. Over 15 such questions it is worth about 6.7 marks.
Be honest about "ruled out". If you rule options out wrongly, your real chance falls below these numbers. Your mock tests show your true hit rate; the score-analysis method explains how to measure it.
Accuracy vs attempt rate
Attempting more questions helps only while your accuracy holds. This table shows the net score for five realistic combinations, on the 200-mark scale:
| Attempted | Accuracy | Correct / wrong | Net score |
|---|---|---|---|
| 100 | 85% | 85 / 15 | 106.7 |
| 115 | 80% | 92 / 23 | 112.4 |
| 130 | 72% | 93.6 / 36.4 | 108.6 |
| 145 | 65% | 94.2 / 50.8 | 103.1 |
| 150 | 60% | 90 / 60 | 93.3 |
In this example, the extra 35 attempts between 115 and 150 added no extra correct answers but 37 more wrong ones, costing about 19 marks. These numbers are an illustration, not a prediction. The useful question is: at what number of attempts does my own accuracy start to fall? Your last two or three mocks will tell you.
Five habits that cut negative marking
- Read the question word twice in statement questions. "Which is not correct", "only 1 and 3" and "both A and R true but R is not the explanation" cause most avoidable errors. Underline the instruction before reading the statements.
- Use elimination on statement combinations. If you are sure statement 2 is wrong, cross out every option that contains 2. Often only one or two options survive.
- Do two passes. In the first pass, answer what you know and mark the rest. In the second, attempt only the marked questions where you can rule out options. Leave the rest for the fifth option.
- Match your confidence to your history. In subjects where your mock accuracy is low, for example current affairs or world geography, set a stricter guessing rule.
- Bubble in batches. Transfer answers to the OMR sheet after every 25 questions so you never rush the last block and misplace a row.
The fifth option is not a free pass
In the 2023 and 2024 papers, every question had a fifth option meaning "question not attempted". It scored zero, while a question with no circle darkened was penalised like a wrong answer. Leaving more than 10% of questions with no circle at all could lead to disqualification. Follow the rules printed in your 2026 booklet. In practice:
- Every row on the OMR sheet should end with exactly one darkened circle, either your answer or option 5.
- Option 5 is the right choice for a true zero-knowledge question. It is not a reason to skip questions where you could eliminate two options.
Practise this before 6 December
Take a free full-length mock test and mark every guess with a small tick. After submitting, count how many ticked questions were right. If fewer than a third were right, your guessing loses marks. If more than half were right, you are probably leaving marks on the table by not attempting more. The last 25 days plan shows where these mocks fit.