The simple and compound interests on a sum of money for $2$ years are ₹ $8400$ and ₹ $8652$ respectively. The rate of interest per annum is (in $\%$):

What sum will give ₹ $244$ as the difference between simple interest and compound interest at $10 \%$ per annum in $1 \frac{1}{2}$ years,compounded half-yearly?

What will be $C.I.$ (in $Rs.$) on an amount of $Rs. 10000$ at the rate of $20$ $p.c.p.a.$ in two years if the interest rate is compounded half-yearly?

Mr. Dua invested money in two schemes $A$ and $B$ offering compound interest at $8 \%$ per annum and $9 \%$ per annum respectively. If the total amount of interest accrued through two schemes together in two years was ₹ $4818.30$ and the total amount invested was ₹ $27000$. What was the amount (in ₹) invested in scheme $A$?

The $S.I.$ is $Rs. 7200$ at $12$ $p.c.p.a.$ for $6$ years on a sum. What is the $C.I.$ (in $Rs.$) on the same sum at $5$ $p.c.p.a.$ for $2$ years?

An amount of money at compound interest grows up to $Rs. 3840$ in $4$ $years$ and up to $Rs. 3936$ in $5$ $years$. Find the rate of interest (in $\%$)?