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?

$A$ 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 $10 \% \, p.a.$)

The $C.I.$ on $Rs. 10000$ at $20 \%$ per annum at the end of $1$ year $6$ months,if the interest is calculated half-yearly,will be:

₹ $3757$ is to be divided between $A$ and $B$ such that $A$'s share at the end of $7$ years may be equal to $B$'s share at the end of $9$ years. If the rate of interest is $10 \%$ per annum compounded annually,what is $B$'s share (in ₹)?

The value of a machine depreciates at the rate of $12\%$ per annum. It was purchased $3$ years ago. Its present value is $Rs. 29644.032$. What was the purchase price (in $Rs.$) of the machine?

$A$ sum put out at $4 \%$ compound interest payable half-yearly amounts to ₹ $6632.55$ in $1 \frac{1}{2}$ years. The sum (in ₹) is