If the simple interest on ₹ $x$ at a rate of $a \%$ for $m$ years is same as that on ₹ $y$ at a rate of $a^2 \%$ for $m^2$ years,then $x: y$ is equal to

If a sum of ₹ $9$ is lent to be paid back in $10$ equal monthly instalments of ₹ $1$ each,then the rate of interest 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?

Two equal sums were lent at simple interest for $4$ years and for $3$ years respectively. The rate of interest in the latter case was $3 \%$ higher than that of the former case,but the amount in each was $Rs. 1088$. Find the rate of interest (in $\%$) of the former case?

$A$ sum fetched a total simple interest of $Rs. 4016.25$ at the rate of $9 \%$ $p.a.$ in $5$ years. What is the sum (in $Rs.$)?

Girish invested some money in a bank. After $8$ years,his amount became triple. How many times of the original sum will the money become in $20$ years at simple interest?