Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: a sum of money deposited at c . i . amounts to rs . 1980 in 3 years and to rs . 2492 in 4 years . find the rate percent ?
25 %
Approx. 12.5% per annum.