The $C.I.$ on $Rs. 10000$ at $20 \%$ per annum at the end of $1$ year $6$ months,if the interest is calculated half-yearly,will be:

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

The population of a town increases by $5 \%$ every year. If the present population is $9261,$ what was the population $3$ years ago?

The difference between the compound interest and simple interest on a certain sum at $3 \%$ per annum for $3$ years is ₹ $27.27$. The sum is (in ₹):

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 $₹ 4,160$?

Which of the statements given below are sufficient to answer the following question?
What is the rate of interest per annum on an investment of $Rs. 800$?
$(I)$ The income from $S.I.$ at the end of $3$ years at the same rate of interest is $19$.
$(II)$ $C.I.$ is $15.76$ more than $S.I.$ on the same sum and same rate in $2$ years.