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 $Rs.$)

$A$ person takes a loan of ₹ $10,000$ at an interest rate of $10 \%$ compounded annually for a period of $4$ years. How much interest (in ₹) does he have to pay?

Abhinav invested a certain amount at the rate of $8$ $p.c.p.a.$ for $5$ years and obtained a $SI$ of $Rs. 3800$. Had he invested the same amount at the same interest rate for $2$ years,how much amount (in $Rs.$) would he have obtained as $CI$ at the end of $2$ years?

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?

Find the difference between $S.I.$ and $C.I.$ (in $Rs.$) at $12 \%$ per annum for $2$ years on $Rs. 10000$.

An amount of ₹ $12500$ is deposited for a period of $2$ years at an interest rate of $4 \%$ per annum. Find the difference between the simple interest and the compound interest (in ₹) for the deposit.