Two equal amounts are deposited in two banks,each at $15 \%$ per annum,for $3 \frac{1}{2}$ years and $5$ years respectively. If the difference between their interests is ₹ $1440$,each sum is (In ₹):

$A$ part of $Rs. 38800$ is lent out at $72 \%$ per annum for six months. The rest of the amount is lent out at $5 \%$ per annum after one year. The ratio of interest after $3$ years from the time when the first amount was lent out is $5: 4$. Find the second part that was lent out at $5 \%$ (in $Rs.$).

$A$ certain sum of money amounts to $Rs. 756$ in $2$ $years$ and to $Rs. 873$ in $3.5$ $years$. Find the rate of interest (in $\%$)?

At what percent of simple interest will a sum of money double itself in $15$ years?

If the simple interest on a certain sum of money is ₹ $256$ and the rate of interest per annum equals the number of years,then the rate of interest (in $\%$) is:

The difference between the interest received from two different banks on $₹ 5,000$ for $2$ $years$ is $₹ 25$. The difference between their rates is (in $\%$):