Albert invested an amount of $x$ rupees in a fixed deposit scheme offering $10 \%$ per annum for the $1^{\text{st}}$ year and $15 \%$ per annum for the $2^{\text{nd}}$ year and received an amount of ₹ $20,240$ after two years. What is $x$ (in ₹)?

The rate of simple interest (in $\%$) for which a sum of money becomes $5$ times of itself in $8$ years is:

The population of a particular area of a city is $5000$. It increases by $10 \%$ in $1^{st} \,yr$. It decreases by $20 \%$ in the $2^{nd} \,yr$ because of some reason. In the $3^{rd} \,yr$ the population increases by $30 \%$. What will be the population of the area at the end of $3$ $years$?

Divide ₹ $2379$ into $3$ parts so that their amounts after $2, 3$ and $4$ years respectively may be equal,the rate of interest being $5 \%$ per annum at simple interest. The first part is (in ₹):

Sumit lends ₹ $10000$ for $2$ $years$ at $20 \%$ per annum simple interest. After $1$ $year,$ he receives ₹ $6000$. How much (in ₹) will he receive next year?

In how much time (in $years$) will a sum of ₹ $9500$ amount to ₹ $17622.5$ at the rate of $4.5 \%$ per annum at simple interest?