The simple interest accrued on an amount of $Rs. 20000$ at the end of $3$ years is $Rs. 7200$. What would be the compound interest accrued on the same amount at the same rate in the same period?

Find the compound interest on $Rs. 32000$ at $20 \%$ per annum for $1$ year,compounded half-yearly (in $Rs.$).

$A$ 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 $years$):

$A$ sum of $Rs. 8448$ is to be divided between $X$ and $Y$ who are respectively $18$ and $19 \,yr$ old,in such a way that if their shares be invested at $6.25 \%$ per annum at compound interest,they will receive equal amounts on attaining the age of $21 \,yr$. The present share of $X$ is (In $Rs.$)

The difference between simple and compound interest compounded annually on a certain sum of money for $2$ years at $4 \%$ per annum is $Rs. 1$. The sum (in $Rs.$) is

If a sum of money at compound interest amounts to thrice itself in $3$ years,then in how many years will it be $9$ times itself?