If $A$'s salary is $20\%$ higher than $B$'s,then how much percent is $B$'s salary less than $A$'s salary?

If the length of a rectangle is increased by $20 \%$ and its breadth is decreased by $10 \%$,what will be the impact on its perimeter?

What percent of $12$ is $84$?

Of the $1000$ inhabitants of a town,$60 \%$ are males of whom $20 \%$ are literate. If,of all the inhabitants,$25 \%$ are literate,then what per cent of the females of the town are literate (in $.5$)?

What percent of Rs. $2650$ is Rs. $1987.50$?

The price of sugar has fallen by $10 \%$. How many quintals can be bought for the same money which was sufficient to buy $18$ quintals at the higher price?