$23 \%$ of $8040 + 42 \%$ of $545 = ? \%$ of $3000$

The length and breadth of a square are increased by $30 \%$ and $20 \%,$ respectively. The area of the rectangle so formed exceeds the area of the square by:

$A$ man spends $75 \%$ of his income. His income is increased by $20 \%$ and he increases his expenditure by $10 \%$. His savings are increased by: (in $\%$)

In a class,$70 \%$ of the students read Hindi,$40 \%$ of the students are boys,and $20 \%$ of the girls do not read Hindi. What percentage of boys read Hindi?

In a recent survey,$40 \%$ of houses contained two or more people. Of those houses containing only one person,$25 \%$ had only a male. What is the percentage of all houses that contain exactly one female and no males (in $\%$)?

$A$ housewife saved $₹ 2.50$ in buying an item on sale. If she spent $₹ 25$ for the item,approximately what percentage did she save in the transaction?