The simple interest on a certain sum for 2 years at 6% per annum comes to Rs. 300. The compound interest at the same rate for the same time on the same sum would be:

The compound interest is Rs. 309.

From SI = P x R x T / 100, 300 = P x 6 x 2 / 100, so P = 2500.

CI = P x ((1.06)^2 - 1) = 2500 x ((1.06)^2 - 1).

(1.06)^2 = 1.1236, so the factor = 0.1236.

CI = 2500 x 0.1236 = Rs. 309.