$A$ sum of ₹ $15000$ deposited at compound interest becomes double after $5$ $years$. After $20$ $years$,it will become (in ₹):

The simple interest accrued on an amount of $Rs. 19800$ at the end of $3$ years is $Rs. 7128$. What would be the compound interest (in $Rs.$) accrued on the same amount at the same rate in the same period?

$A$ sum of $Rs. 1000$ after $3 \, \text{years}$ at compound interest becomes a certain amount that is equal to the amount that is the result of a $3 \, \text{year}$ depreciation from $Rs. 1728$. Find the difference between the rates (in $\%$) of $C.I.$ and depreciation? (Given $C.I.$ is $10 \% \, p.a.$)

What sum will give ₹ $244$ as the difference between simple interest and compound interest at $10 \%$ per annum in $1 \frac{1}{2}$ years,compounded half-yearly?

The difference between the simple interest on a certain sum at the rate of $10 \%$ per annum for $2$ years and compound interest which is compounded every $6$ months is ₹ $124.05$. What is the principal (in ₹)?

The difference between simple and compound interest compounded annually on a certain sum of money for $2$ years at $4 \%$ per annum is $Rs. 1$. The sum (in $Rs.$) is