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?

If the compound interest on a certain sum of money for $3$ years at $5 \,%$ p.a. is $Rs. 504.40$ , find the corresponding simple interest. (In $Rs.$)

In how many years will ₹ $2,000$ yield ₹ $662$ as compound interest at $10 \%$ per Annum compounded annually?

How many statements are useful for find this : 

What is the rate of interest percent $p.a.$?

$Statements:$

$I$. The difference between the compound interest and simple interest earned in two years on the amount invested is ₹ $100$.

$II$. The amount becomes ₹ $19,500$ in three years on simple interest.

$III$.The simple interest accrued in two years on the same amount at the same rate of interest is ₹ $3,000$.

What sum will amount (In ₹) to ₹ $15916.59$ in $3$ years at compound interest, the interest for first, second and third year being $3,2$ and $1$ per cent, respectively?

The difference between simple interest and compound interest compounded annually on a certain sum of money for $2$ years at $4 \%$ per annum is ₹ $1 .$ The sum (in ₹) is