Explanation:

To find the sum, we need to analyze the difference between compound interest (CI) and simple interest (SI) over 2 years at a 10% rate, which is given as Rs.250.

- Formula for Simple Interest (SI):

- SI = P * R * T / 100

- Where P is principal, R is rate, and T is time.

- Formula for Compound Interest (CI):

- CI = P * (1 + R/100)^T - P

- Difference between CI and SI after 2 years:

- Difference = P * [(1 + R/100)^2 - (1 + 2R/100)]

- Given Difference = Rs.250, we need to calculate the principal (P).

Let's calculate:

- Put [(1 + 10/100)^2 - (1 + 20/100)] = 250 / P

- Which gives P = 25000

Option 3 is therefore the correct answer.

Answer: Rs.25,000