If the simple interest on a sum of money for $2$ years at $5 \%$ per annum is ₹ $50$,what is the compound interest (in ₹) on the same sum at the same rate and for the same time?

What is the rate of interest (in $\%$) if simple interest earned on a certain sum for the $3^{rd}$ year is $₹ 2,000$ and compound interest earned in $2$ years is $₹ 4,160$?

Find the difference (in $Rs.$) between $C.I.$ and $S.I.$ on $Rs. 13000$ at $4 \%$ per annum for $3$ years.

$A$ man borrows $Rs. 5100$ to be paid back with compound interest at the rate of $4 \%$ p.a. by the end of $2$ years in two equal yearly instalments. How much (in $Rs.$) will be each instalment?

What is the difference between the compound interests (in ₹) on ₹ $5000$ for $1 \frac{1}{2}$ years at $4 \%$ per annum compounded yearly and half-yearly?

$A$ bank offers $5 \%$ compound interest calculated on a half-yearly basis. $A$ customer deposits $Rs. 1600$ each on $1^{st}$ January and $1^{st}$ July of a year. At the end of the year,the amount (in $Rs.$) he would have gained by way of interest is: