The difference of compound interest (in ₹) on ₹ $800$ for $1$ year at $20 \%$ per annum when compounded half-yearly and quarterly is:

$A$ sum of money at compound interest amounts in two years to Rs. $2809,$ and in three years to Rs. $2977.54.$ Find the rate of interest and the original sum.

$A$ sum of money placed at compound interest doubles itself in $5$ years. It will amount to eight times itself at the same rate of interest in (in $years$):

If the difference between $S.I.$ and $C.I.$ for $2$ years on a sum of money lent at $5 \%$ per annum is $₹ 6$,then the sum is:

Sita deposited $Rs. 5000$ at $10\%$ simple interest for $2$ years. How much more money (in $Rs.$) will Sita have in her account at the end of $2$ years,if it is compounded semi-annually?

Sonika invested an amount of ₹ $5800$ for $2$ years. At what rate of compound interest ($\%$ per annum) will she get an amount of ₹ $594.5$ as interest at the end of two years?