If the simple interest on a certain sum of money is $\frac{4}{25}$ of the sum and the rate per cent equals the number of years,then the rate of interest (in $\%$) per annum is

What annual payment (in $Rs.$) will discharge a debt of $Rs. 770$ due in $5$ years,the rate of interest being $5 \%$ per annum?

$A$ 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 $\%$)?

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?

The simple interest on a sum is $\frac{1}{16}$ of the principal and the number of years is equal to the rate per cent per annum. The rate per cent per annum is (in $.5$)

$A$ sum of money lent out at simple interest amounts to $Rs. 720$ after $2$ years and $Rs. 1020$ after a further period of $5$ years. Find the principal (in $Rs.$).