The compound interest on a certain sum for $2$ years at $10 \%$ per annum is ₹ $525$. The simple interest (in ₹) on the same sum for double the time at half the rate percent per annum is

Rohit invested some amount at the rate of $6\%$ per annum and at the end of $3$ years he received ₹ $8730$ as simple interest. How much compound interest (in ₹) will he receive on the same amount and same rate of interest after $2$ years?

$A$ sum of ₹ $1260$ is borrowed from a money lender at $10 \%$ p.a. compounded annually. If the amount is to be paid back in two equal annual instalments,find out the annual instalment (in ₹).

Monica deposited a total of $Rs. 10500$ with a bank in two different deposit schemes at $10 \%$ $p.a.$,interest being compounded annually. As per the schemes,she gets the same amount after $2 \,years$ on the first deposit as she gets after $3 \,years$ on the second deposit. How much money (In $Rs.$) did she deposit for $3 \,years$?

An amount of money at compound interest grows up to ₹ $3,840$ in $4$ years and up to ₹ $3,936$ in $5$ years. Find the rate of interest (in $\%$).

The population of a country is $10$ crore and it is expected that the population will become $13.31$ crore in $3$ years. What will be the annual growth rate in percent?