$A$ lent ₹ $6000$ to $B$ for $2$ $years$ and ₹ $1500$ to $C$ for $4$ $years$ and received altogether from both ₹ $900$ as simple interest. The rate of interest is (in $\%$):

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

Rakesh borrowed ₹ $5000$ from Ganesh at simple interest. If Ganesh received ₹ $500$ more than his capital after $5$ years,then the rate of interest (in $\%$) per annum is:

$A$ person invests $Rs. 2,00,000$ at $12 \%$ $p.a.$ for $1$ $year$. If he invests $Rs. 500$ more,he is eligible for $13 \%$ $p.a.$ interest. How much more interest (in $Rs.$) would he receive if he accepted the second option?

If the simple interest on a certain sum of money after $6 \frac{1}{4}$ years is $\frac{3}{8}$ of the principal,then the rate of interest (in $\%$) per annum is