Partial marking in JEE Advanced: when to mark one, two or three options

Summary: Any wrong option costs you −1 for the whole question. Marking only the options you are sure of gives partial credit. As a rough rule, add an uncertain option only if you are more than about 62% sure of it when you already have one sure option, about 71% when you have two, and about 83% when you have three.

The scheme

This is the scheme printed in the JEE (Advanced) 2026 papers for questions with one or more correct options out of four. The same scheme appeared in the 2023, 2024 and 2025 papers. Check the instructions on exam day, since the IITs can change it.

Two things follow directly. First, marks are given per correct option you choose, as long as you choose no wrong one. Second, a single wrong option wipes out everything, however many right ones you also marked. Note also that if only one option is correct and you mark just that one, you get the full +4.

How to think about "how sure am I"

In the exam hall you rarely know for certain. More often you are sure of one or two options and doubtful about another. The question is whether adding the doubtful option improves your expected score. We write p for the probability, as you judge it, that the doubtful option is correct, and assume the options you have left out are ones you are confident are wrong.

Example 1: one sure option, one doubtful

You are sure (A) is correct, sure (C) and (D) are wrong, and unsure about (B).

• If (B) is correct, the answer is A, B. Marking only A gives +1. Marking A and B gives +4.
• If (B) is wrong, the answer is A alone. Marking only A gives +4. Marking A and B gives −1.

Expected marks for marking A only = p × 1 + (1 − p) × 4 = 4 − 3p.

Expected marks for marking A and B = p × 4 + (1 − p) × (−1) = 5p − 1.

These are equal when 4 − 3p = 5p − 1, that is p = 5/8, or 62.5%. Add (B) only if you are more than about 62% sure of it.

Example 2: two sure options, one doubtful

You are sure of (A) and (B), sure (D) is wrong, unsure about (C).

• If (C) is correct: marking A, B gives +2; marking A, B, C gives +4.
• If (C) is wrong: marking A, B gives +4; marking A, B, C gives −1.

Expected marks: A, B only = 2p + 4(1 − p) = 4 − 2p. A, B, C = 5p − 1. Equal at p = 5/7, about 71%.

Example 3: three sure options, one doubtful

You are sure of (A), (B) and (C), unsure about (D).

• If (D) is correct: marking three gives +3; marking all four gives +4.
• If (D) is wrong: marking three gives +4; marking four gives −1.

Expected marks: three options = 3p + 4(1 − p) = 4 − p. Four options = 5p − 1. Equal at p = 5/6, about 83%.

The bar rises because the more you already have, the more you stand to lose by adding a wrong option, and the less you gain from adding a right one.

Example 4: nothing certain

You are not certain of any option but lean towards (A), at about 70%. Should you mark (A) alone or leave the question?

If (A) is correct, you get at least +1 (and +4 if it happens to be the only correct option). If (A) is wrong, you get −1. Taking the worst case of +1, the expected score is 0.7 × 1 + 0.3 × (−1) = +0.4. Marking a single option you believe in more than 50% has a positive expected value even in the worst case. Marking two options you each only half believe is a much worse bet, since both have to be right.

Estimating p realistically

The arithmetic is only as good as your estimate. Most students overrate how sure they are, especially late in the paper. A useful check during mock analysis: every time you mark a "doubtful" option, write a small d next to it on your rough sheet. After ten mocks, count how often those doubtful options were right. If it is around half, your "doubtful" means about 50%, and by the table above you should usually leave those options out.

Also look for linked options. In many questions, two options are near-opposites (for example, one says a quantity increases and another says it decreases). If you are sure one is wrong, that often tells you about the other, and your p is higher than it first feels.

A routine for these questions

1. Judge each option separately as sure right, sure wrong or doubtful. Do not look for "the answer".
2. Mark all the sure-right options.
3. For a doubtful option, estimate p and use the table.
4. If every option is doubtful, mark the single one you believe in most only if you rate it above 50%. Otherwise leave the question.

For more on how the rest of the paper changes from year to year, read why every JEE Advanced paper looks different.

Common questions