Question

A sum is invested at compounded interest payable annually.The interest in the first two successive years was Rs.$400$ and Rs.$200$.Find the sum.

Answer 1

Simple interest on Rs 400 for 1 year = 420-400= Rs 20

Rate = $\frac{100\times SI}{PT}=\frac{100\times 80}{400\times 1}=5$%

Rs 400 is the intrest on the sum for 1st year

Hence, sum = $\frac{100\times S.T}{RT}=\frac{100\times 400}{5\times 1}=Rs8000$