On a sum of money, the simple interest for 2 years is Tk. 880, while the compound interest is Tk. 928.4, the rate of interest being the same in both cases. The rate of interest is -

Question: On a sum of money, the simple interest for 2 years is Tk. 880, while the compound interest is Tk. 928.4, the rate of interest being the same in both cases. The rate of interest is -

Solution:
Difference of Compound interest and Simple interest for 2 years = Tk. (928.4 - 880) = Tk. 48.4
Simple interest for 1 years = 880/2 = Tk. 440

Simple interest on 440 for 1 year = 48.4
Interst rate = {(48.4 × 100)/440}% = 11%