There is a $60 \%$ increase in an amount in $6$ years at simple interest. What will be the compound interest (in ₹) of ₹ $12000$ after $3$ years at the same rate?

Amit invested an amount of $Rs. 25000$ in a fixed deposit at a compound interest rate of $8 \%$ per annum for $2$ years. What amount (in $Rs.$) will Amit receive at the end of the period?

The difference between the compound interest and simple interest on a certain sum at $5 \%$ per annum for $2$ years is ₹ $1.50$. The sum is (in ₹):

$A$ sum of $Rs. 1000$ after $3 \, \text{years}$ at compound interest becomes a certain amount that is equal to the amount that is the result of a $3 \, \text{year}$ depreciation from $Rs. 1728$. Find the difference between the rates (in $\%$) of $C.I.$ and depreciation? (Given $C.I.$ is $10 \% \, p.a.$)

In a certain number of years,a sum of money doubles itself at $6 \frac{1}{4} \%$ simple interest per annum. The required time (in $years$) is:

$A$ person takes a loan of ₹ $10,000$ at an interest rate of $10 \%$ compounded annually for a period of $4$ years. How much interest (in ₹) does he have to pay?