If the difference between the $C.I.$ compounded half-yearly and simple interest on a sum at $10 \%$ per annum for one year is $Rs. 25$,the sum (in $Rs.$) is:

What is $C.I.$ (in $Rs.$) on $Rs. 7500$ for $4$ years if the rate of interest is $10 \%$ p.a. for the first $2$ years and $20 \%$ p.a. for the next $2$ years?

$B$ borrows ₹ $5,000$ from $A$ at $6 \%$ p.a. simple interest and lends it to $C$ at compound interest of $10 \%$ p.a. If $B$ collects the money back from $C$ after $2$ years and repays $A$,the profit made by $B$ in the transaction is (in ₹):

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 is the difference between the simple and the compound interest (in ₹) on ₹ $7,300$ at the rate of $6$ $p.c.p.a.$ in $2$ years?

On a certain principal,if the simple interest for two years is ₹ $1400$ and the compound interest for two years is ₹ $1449$,what is the rate of interest (in $\%$) ?