Asmita invests an amount of $Rs. 9535$ at the rate of $4\%$ per annum to obtain a total amount of $Rs. 11442$ on simple interest after a certain period. For how many years did she invest the amount to obtain the total sum?

₹ $8000$ amounts to ₹ $9200$ in $3$ years at simple interest. If the interest rate is increased by $3 \%$,to how much would it amount (in ₹)?

$Rs. 600$ becomes $Rs. 720$ in $4$ $years$ at simple interest. If the rate of interest is increased by $2 \%$,what will be the total amount (in $Rs.$)?

$A$ sum of money lent out at simple interest amounts to ₹ $720$ after $2$ $years$ and to ₹ $1,020$ after a further period of $5$ $years$. The sum is (In ₹)

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

During the first year,the population of a village is increased by $5 \%$ and in the second year it is diminished by $5 \%$. At the end of the second year,its population was $47880$. What was the population at the beginning of the first year?