The difference between the compound and simple interest on a sum of money for $2$ years at $6 \frac{1}{4} \%$ per annum is $Rs. 10$. The sum (in $Rs.$) is

How many statements are required to find 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 ₹ $3,000$.

Rohit invested some amount at the rate of $6\%$ per annum and at the end of $3$ years he received ₹ $8730$ as simple interest. How much compound interest (in ₹) will he receive on the same amount and same rate of interest after $2$ years?

What will be the amount (in ₹) if a sum of ₹ $5000$ is placed at compound interest for $3$ years,while the rate of interest for the first,second,and third years is $2\%$,$3\%$,and $4\%$ per annum,respectively?

The difference between compound interest and simple interest on a sum for $2$ years at $10 \%$ per annum,when the interest is compounded annually,is ₹ $20$. If the interest were compounded half-yearly,the difference in the two interests (in ₹) will be:

$A$ sum of money invested at compound interest amounts to ₹ $800$ in $3$ years and to ₹ $840$ in $4$ years. The rate of interest (in $\%$) per annum is