$A$ 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?

Raghu invested a certain sum in Scheme $X$ for $4$ years. Scheme $X$ offers simple interest at $12\%$ per annum for the first two years and compound interest (compounded annually) at $20\%$ per annum for the next two years. The total interest earned by him after $4$ years is $₹ 11016$. What was the sum (in $₹$) invested by Raghu in Scheme $X$?

The compound interest earned by Shivam on a certain amount at the end of $2$ years at the rate of $8 \, p.c.p.a.$ was $Rs. 1414.4$. What was the total amount that Shivam got back at the end of $2$ years in the form of principal plus interest earned (in $Rs.$) (in $.4$)?

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 $2010$?

If a sum of money placed at compound interest,compounded annually,doubles itself in $5$ years,then the same amount of money will be $8$ times of itself in how many years?

The compound interest on a sum of money for $3$ years at $5 \%$ per annum is ₹ $1324.05$. What is the simple interest (in ₹)?