Rahul invested equal sums of money at compound interest under two schemes A and B. Under scheme A, the interest rate was 10% per annum and under scheme B, the interest rate was 12% per annum. The compound interest after two years on the sum invested in scheme A was Rs. 1,050. How much is the interest earned under scheme B after two years, if the interest is compounded annually in both schemes?

Solution (By Examveda Team)

$$\eqalign{ & {\text{CI of A in two years}} \cr & = 10 + 10 + \frac{{10 \times 10}}{{100}} \cr & = 21\% \cr & 21\% \to 1050 \cr & 1\% \to 50 \cr & 100\% \to {\text{Rs}}{\text{. 5000}} \cr & {\text{P}} = {\text{Rs}}{\text{. 5000}} \cr & {\text{CI of B in two years}} \cr & = 12 + 12 + \frac{{12 \times 12}}{{100}} \cr & = 24 + 1.44 \cr & = 25.44\% \cr & {\text{CI}} = \frac{{5000 \times 25.44}}{{100}} = {\text{Rs}}{\text{. 1272}} \cr} $$