At what rate per cent per annum will ₹ $1000$ amount to ₹ $1331$ in $3$ years? The interest is compounded yearly.

What will be the amount (in ₹) if a sum of ₹ $5000$ is placed at compound interest for $3$ years,while the rate of interest for the first,second,and third years is $2\%$,$3\%$,and $4\%$ per annum,respectively?

$A$ 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?

The difference between the $S.I.$ and $C.I.$ obtained on a principal amount at $5$ $p.c.p.a.$ after $2$ years is $Rs. 35$. What is the principal amount (in $Rs.$)?

$A$ certain sum will amount to ₹ $12,100$ in $2$ years at $10 \%$ per annum of compound interest,interest being compounded annually. The sum is (In ₹)

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 ₹ $3,000$.