There is a $60 \%$ increase in an amount in $6$ years at simple interest. What will be the compound interest (in $Rs.$) on $Rs. 12,000$ after $3$ years at the same rate?

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?

Sonika invested an amount of ₹ $5800$ for $2$ years. At what rate of compound interest ($\%$ per annum) will she get an amount of ₹ $594.5$ as interest at the end of two 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 $B$?

₹ $6,100$ was partly invested in Scheme $A$ at $10 \%$ p.a. compound interest (compounded annually) for $2$ years and partly in Scheme $B$ at $10 \%$ p.a. simple interest for $4$ years. Both the schemes pay equal interests. How much was invested (in ₹) in Scheme $A$?

The difference between the simple interest and the compound interest (in ₹) on ₹ $600$ for $1$ year at $10 \%$ per annum,reckoned half-yearly is