If the price of a book is first decreased by $25 \%$ and then increased by $20 \%,$ then the net change in the price will be

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

In an examination,it is required to get $35 \%$ of the aggregate marks to pass. Rishu got $216$ marks and was declared failed by $5 \%$ marks. What was the total marks?

If $35 \%$ of a number is $175,$ then what percent of $175$ is that number (in $\%$)?

An empty fuel tank of a car was filled with an ordinary type of petrol. When the tank was one-third empty,it was filled with high-speed petrol. Again,when the tank was one-third empty,it was filled with an ordinary type of petrol. Again,when the tank was one-third empty,it was filled with high-speed petrol. At this time,what was the percentage of high-speed petrol in the tank?

$1200$ boys and $650$ girls appeared in an examination. If $70 \%$ of boys and $40 \%$ of girls failed,find the approximate percentage of passed students.