The Arithmetic of the 30 Percent Cut-off
The Arithmetic of the 30 Percent Cut-off
Part-I is only a qualifying paper — thirty questions, and thirty percent needed to pass. But because of negative marking, thirty percent does not mean nine correct answers. This topic sets out that arithmetic, because no strategy can be built without knowing the real number.
The Marking Scheme
| Situation | Marks |
|---|---|
| Correct answer | +1 |
| Wrong answer (A to D) | −1/3 |
| Option E marked | 0 |
| Bubble left completely blank | −1/3 |
The point to notice is that leaving a bubble blank and marking a wrong answer carry the same deduction of a third of a mark. But marking option E costs nothing. That single difference changes the whole strategy.
✗ Nothing is lost by skipping a question | ✓ A blank bubble costs a third of a mark; to skip without loss you must mark option E
Case One: An Answer Marked on Every Question
Suppose a candidate marks something on all thirty questions and x of them turn out correct. The remaining thirty minus x will be wrong.
Score = x − (30 − x) / 3 = (4x / 3) − 10
Qualifying needs a score of nine or more. Solving for x gives at least 14.25, which means fifteen correct answers.
| Correct | Score | Result |
|---|---|---|
| 14 | 8.67 | fail |
| 15 | 10.00 | pass |
| 18 | 14.00 | safe |
| 20 | 16.67 | comfortable |
So a candidate who marks a bubble by guesswork on every question needs fifteen out of thirty — half the paper. That number is far higher than most candidates expect.
Case Two: Option E on the Unknown Questions
Now suppose the same candidate marks answers only on the questions he actually knows and marks option E on all the rest. Then nothing is deducted at all.
Score = number of correct answers
In this case only nine correct answers are needed to qualify. That is the most useful sentence in this whole chapter — using option E properly brings the requirement down from fifteen to nine.
15 सही उत्तर लाना आधा पत्र जानना है; 9 सही उत्तर लाना एक तिहाई से भी कम है। पूरा फ़र्क़ केवल इस बात से आता है कि न आने वाले प्रश्नों पर आप E भरते हैं या तुक्का लगाते हैं।
TRE pointer: Hold two numbers — fifteen correct if you guess everywhere, nine if you use option E properly. This arithmetic comes from the new five-option system, so it will not be found in older material. Before the exam, check the marking scheme once against your admit card and the official notification.
60-Second Recap
- Correct +1, wrong −1/3, option E zero, blank bubble −1/3.
- A blank bubble and a wrong answer carry the same deduction.
- Marking every question needs fifteen correct answers to qualify.
- Fourteen correct gives 8.67, which falls short of nine.
- Using option E on unknown questions needs only nine correct.
- Option E cuts the requirement from fifteen down to nine.
Frequently Asked Questions
How many correct answers are needed to pass Part-I?
It depends on what you do with the questions you cannot answer. If you mark something on all thirty, you need fifteen correct. If you mark option E on the ones you do not know, nine correct answers are enough.
Why is fourteen correct not enough?
Because the remaining sixteen wrong answers cost about 5.33 marks at a third each, leaving a score of 8.67, which is below the cut-off of nine. Fifteen correct answers give ten by the same calculation and carry the candidate safely across.
Is it safe to leave a question blank?
No. A completely blank bubble costs the same third of a mark that a wrong answer does. If a question is to be skipped, mark option E, which carries no deduction at all. Leaving a bubble blank is the worst choice available in this system.
Do Part-I marks count towards the merit list?
No. Part-I is only qualifying and its marks are not added to the final merit list, which is built from Part-II and Part-III. So the aim here is not to maximise the score but to cross thirty percent safely and move on.