The tax on a commodity is diminished by $10 \%$ and its consumption increases by $10 \%$. Find the effect on revenue.

In measuring the sides of a rectangle,one side is taken $10 \%$ in excess and the other $20 \%$ in deficit. Find the error per cent in area calculated from the measurement.

$A$ shopkeeper undertakes to supply $2000$ tables at $Rs. 1725$ each. He estimates that if $10\%$ are defective,which will be sold at $50\%$ of the original price,then the profit will be $15\%$ on his whole outlay. When the tables were supplied,$70\%$ of the tables were found defective. What loss did the shopkeeper incur?

$16 \frac{2}{3} \%$ of $600 \, \text{gm} - 33 \frac{1}{3} \%$ of $180 \, \text{gm}$

The product of one-third of a number and $150 \%$ of another number is what percent of the product of the given numbers?

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?