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?

If $Rs. 3000$ amounts to $Rs. 4320$ at compound interest in a certain time,then what will $Rs. 3000$ amount to in half of that time (in $Rs.$)?

$A$ man gets a simple interest of $Rs. 1000$ on a certain principal at the rate of $5$ $p.c.p.a.$ in $4$ years. What compound interest (in $Rs.$) will the man get on twice the principal in two years at the same rate?

$A$ sum of money is paid back in two annual instalments of ₹ $17,640$ each,allowing $5 \%$ compound interest compounded annually. The sum borrowed was (in ₹):

The compound interest (in ₹) on ₹ $6250$ at $12 \%$ per annum for $1$ year,compounded half-yearly is

How many statements are required to find the rate of interest percent $p.a.$?
$Statements:$
$I$. The difference between the compound interest and simple interest earned in two years on the amount invested is ₹ $100$.
$II$. The amount becomes ₹ $19,500$ in three years on simple interest.
$III$. The simple interest accrued in two years on the same amount at the same rate of interest is ₹ $3,000$.