Water tax is increased by $20 \%$ but its consumption is decreased by $20 \%$. The increase or decrease in the expenditure is:

The population of a town is decreased by $20 \%$ and $25 \%$ in two successive years. What per cent population is decreased after two years?

The $75 \%$ of a number is $380$ more than $35 \%$ of the same number. What is $20 \%$ of that number?

In my office,at least $50 \%$ of the people read an e-newspaper. Among those who read an e-newspaper,at most $25 \%$ read more than one e-paper. Only one of the following statements follows from the statements given below. Which one is it?

How much pure alcohol has to be added to $400 \text{ ml}$ of a solution containing $15 \%$ alcohol to change the concentration of alcohol in the mixture to $32 \%$?

The strength of a school increases and decreases in every alternate year by $10 \%$. It started with an increase in $2000$. Then the strength of the school in $2003$ as compared to that in $2000$ was