The rate percent per annum at which ₹ $1200$ amounts to ₹ $1440$ in $4$ years is:

$A$ 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?

Simple interest on a certain sum is $\frac{16}{25}$ of the sum. If the rate per cent and time (in years) are equal,then the rate per cent is:

What is the simple interest (in ₹) on ₹ $5400$ in $5$ years at the rate of $12 \%$ per annum?

The principal (in ₹) that will yield ₹ $60$ as simple interest at $6 \%$ per annum in $5$ years is

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