The annual payment that will discharge a debt of ₹ $47250$ due in $3$ years at the rate of $5 \%$ simple interest per annum is:

Nitin borrowed some money at the rate of $6 \% \text{ p.a.}$ for the first $3 \text{ years}$,$9 \% \text{ p.a.}$ for the next $5 \text{ years}$,and $13 \% \text{ p.a.}$ for the period beyond $8 \text{ years}$. If the total interest paid by him at the end of $11 \text{ years}$ is $₹ 8,160$,how much money (in $₹$) did he borrow?

If the interest on ₹ $12000$ is more than the interest on ₹ $10000$ by ₹ $500$ in $3$ $years$,the rate percent per annum is:

$A$ sum of money doubles itself in $8$ years. In how many years will it treble?

$A$ certain sum doubles in $7$ years at simple interest. The same sum under the same interest rate will become $4$ times in how many years?

In what time will ₹ $8100$ produce the same income at $3 \%$ as ₹ $225$ in $4$ years at $3 \%$?