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:

Ravi invested a total amount of $Rs. 65,000$ in three different schemes $A, B, C$ with rates of interest $12\%$,$16\%$,and $18\%$ per annum respectively,and earned a total interest of $Rs. 10,180$ in one year. If the amount invested in scheme $A$ is $72\%$ of the amount invested in scheme $C$,then what was the amount (in $Rs.$) invested in scheme $B$ (in $,000$)?

Gaurav borrowed $Rs. 800$ at $6 \%$ and Naresh borrowed $Rs. 600$ at $10 \%$. After how much time will they both have equal debts?

If ₹ $500$ amounts to ₹ $725$ at $9 \%$ simple interest in some time,what will ₹ $600$ amount (in ₹) to at $11 \%$ in the same time?

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

The simple interest on a sum of money is $\frac{8}{25}$ of the sum. If the number of years is numerically half the rate percent per annum,then the rate percent per annum is