$A$ 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?

The difference between simple interest and compound interest on a certain sum for $3$ years at $5 \%$ per annum is ₹ $122$. Find the sum (in ₹).

The compound interest on ₹ $4000$ for $4$ years at $10 \%$ per annum will be (in ₹):

The simple interest accrued on an amount of $Rs. 20000$ at the end of $3$ years is $Rs. 7200$. What would be the compound interest accrued on the same amount at the same rate in the same period?

$A$ sum of money lent at compound interest amounts to ₹ $1460$ in $2$ years and to ₹ $1606$ in $3$ years. The rate of interest (in $\%$) per annum is:

$A$ man borrows ₹ $25000$ at $20 \%$ compound interest. At the end of every year,he pays ₹ $5000$ as part repayment. How much (in ₹) does he still owe after three such instalments?