$A$ sum of money at compound interest doubles itself in $15$ years. It will become eight times of itself in (in $years$):

$A$ sum of money lent at compound interest amounts to ₹ $1460$ in $2$ years and to ₹ $1606$ in $3$ years. The rate of interest (in $\%$) per annum is:

In the year $2008$,$5000$ students were admitted to a college. It is found that the number of students admitted is constantly increasing by $24\%$ per year. How many students will be admitted to the college in the year $2010$?

$A$ certain sum of money (in $Rs.$) gives $Rs. 500$ as Simple Interest $(S.I.)$ at $5 \%$ per annum for $1$ year. What is the Compound Interest $(C.I.)$ on the same sum at the same rate at the end of $2$ years?

Aditya invested a certain amount in two different schemes $A$ and $B$. Scheme $A$ offers $S.I.$ at $12$ $p.c.p.a.$ and scheme $B$ offers $C.I.$ at $10$ $p.c.p.a.$ The interest accrued on the amount invested in scheme $A$ in $2$ years was $Rs. 3600$ and the total amount invested was $Rs. 35000$. What was the interest accrued on the amount (in $Rs.$) invested in scheme $B$?

The compound interest on ₹ $4000$ for $4$ years at $10 \%$ per annum will be (in ₹):