A sum of money invested at compound interest amounts to ₹ $800$ in $3$ years and to ₹ $840$ in 4 years. The rate of interest (In $\%$) per annum is

Aditya invest $Rs. 50,000$ in a fixed deposit at $10 \%$ $C.I.$ for $2$ years. At the end of $2$ years she put the money in another deposit at $12 \%$ $S.I.$ for $3$ years. What was the final value (In $Rs.$)  of the initial Investment?

The compound interest accrued on an amount at the end of $3$ $years$ $@$ $15$ $p.c.p.a.$ is $Rs. 6500.52 .$ What is the amount (In $Rs.$) ?

Which of the statement given below are sufficient to answer the following question.

What is the rate of interest $p.c.p.a.$ on the amount of $Rs. 15000$ taking loan?

($I$) The difference between $C.I. \& S.I.$ is $Rs. 170$

($II$) The $S.I.$ of $2$ years is $Rs. 2500$

The principal that amounts to ₹ $4913$ in $3$ years at $6 \frac{1}{4} \%$ per annum compound interest compounded annually (In ₹) is.

A bank offers $5 \%$ compound interest calculated on half-yearly basis. A customer deposits ₹ $1600$ each on $1^{st}$ January and $1^{st}$ July of a year. At the end of the year, the amount (In ₹) he would have gained by way of interest is