$A$ man took a loan from a bank at the rate of $12 \%$ $p.a.$ simple interest. After $3$ $years$ he had to pay ₹ $5400$ interest only for the period. The principal amount (in ₹) borrowed by him was:

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?

$A$ sum of money becomes $\frac{8}{5}$ of itself in $5$ $years$ at a certain rate of interest. The rate per cent per annum is

Simple interest received by a person in $10$ $years$ on a principal of ₹ $9500$ is $130 \%$ of the principal. What is the rate of interest (in $\%$) per annum?

$A$ sum was doubled with $12 \frac{1}{2} \%$ rate of simple interest per annum. The time taken (in years) for that sum is:

Ravi invested a total amount of $Rs. 65,000$ in three different schemes $A, B, C$ with rates of interest $12\%$,$16\%$,and $18\%$ per annum respectively,and earned a total interest of $Rs. 10,180$ in one year. If the amount invested in scheme $A$ is $72\%$ of the amount invested in scheme $C$,then what was the amount (in $Rs.$) invested in scheme $B$ (in $,000$)?