If the simple interest of ₹ $1$ for $1$ month is $1$ paisa,then the rate per cent per annum will be:

$A$ took two loans altogether of ₹ $1200$ from $B$ and $C$. $B$ claimed $14 \%$ simple interest per annum,while $C$ claimed $15 \%$ per annum. The total interest paid by $A$ in one year was ₹ $172$. How much did $A$ borrow from $B$?

The population of a town is $11200$. It increases by $25\%$ in the first year and decreases by $15\%$ in the second year. What is the population of the town at the end of $2$ years?

$A$ sum of ₹ $8000$ is divided into two parts. The simple interest on the first part at the rate of $21 \%$ per annum is equal to the simple interest on the second part at the rate of $35 \%$ per annum. What is the interest (in ₹) of each part?

$A$ sum of money put at simple interest trebles itself in $15$ years. The rate per cent per annum is (in $\%$):

What annual payment (in $Rs.$) will discharge a debt of $Rs. 1092$ due in $2 \,yr$ at $12 \%$ simple interest?