Explanation:

- In the absence of a partnership deed, no interest is generally credited on capital unless agreed otherwise.

- Option 1: Rs 3,000 - Assumes an interest rate of 6% on Rs 50,000 for 10 months. This is incorrect without a predefined agreement.

- Option 2: Zero - In the absence of a deed, partners receive no interest on additional capital. This is correct.

- Option 3: Rs 2,500 - Suggests an assumption of 5% annual interest, calculated over the full year, incorrect without an agreement.

- Option 4: Rs 1,800 - Assumes an alternative interest calculation, not applicable without prior consent.

Correct Answer: Option 2: Zero