If the compound interest on a principal amount for 2 years at an annual rate of 10% is Rs. 525, what is the simple interest on the same principal for 4 years at an annual rate of 5%?

Explanation

Let the principal be Rs. P. The compound interest for 2 years at 10% per annum is given by P[(1 + 10/100)^2 - 1] = 525. Calculating, P[(11/10)^2 - 1] = 525, which simplifies to P * (21/100) = 525. Therefore, P = 525 * 100 / 21 = Rs. 2500. Now, the simple interest for 4 years at 5% per annum is (2500 * 5 * 4) / 100 = Rs. 500.