The population of a town increases $4 \%$ annually but is decreased by emigration annually to the extent of $(1/2) \%$. What will be the increase per cent in $3$ years?

Rice is now being sold at $Rs. 30$ per $kg$. During last month,its rate was $Rs. 26$ per $kg$. Find by how much percentage must a family reduce its consumption to keep the expenditure fixed?

In an examination,the percentage of students qualified to the number of students appeared from school $A$ is $70 \%$. In school $B$,the number of students appeared is $20 \%$ more than the students appeared from school $A$ and the number of students qualified from school $B$ is $50 \%$ more than the students qualified from school $A$. What is the percentage of students qualified to the number of students appeared from school $B$?

In a certain quantity of ghee, $60 \%$ is pure ghee and $40 \%$ is vanaspati. If $10 \text{ kg}$ of pure ghee is added, the concentration of vanaspati ghee becomes $20 \%$. What was the original quantity (in $\text{ kg}$)?

In expressing a length $81.472 \, km$ as nearly as possible with three significant digits,find the percentage error?

If the side of a square is increased by $30 \%,$ its area is increased by: