The sum of money that will produce ₹ $1770$ interest in $7 \frac{1}{2}$ years at $8 \%$ simple interest per annum is:

The population of a town is $11200$. It increases by $25\%$ in the first year and decreases by $15\%$ in the second year. What is the population of the town at the end of $2$ years?

What is the simple interest (in ₹) on ₹ $5400$ in $5$ years at the rate of $12 \%$ per annum?

$A$ person invests $Rs. 2,00,000$ at $12 \%$ $p.a.$ for $1$ $year$. If he invests $Rs. 500$ more,he is eligible for $13 \%$ $p.a.$ interest. How much more interest (in $Rs.$) would he receive if he accepted the second option?

What is the present worth (in ₹) of ₹ $132$ due in $2$ years at $5\%$ simple interest per annum?

$A$ sum of ₹ $1,550$ is lent out in two parts,one at $8 \%$ and another at $6 \%$. If the total annual income is ₹ $106$,find the money lent at each rate.