$A$ single discount,equivalent to a successive discount of $40 \%$ and $30 \%$ is in $\%$?

$A$ sells a good to $B$ at a profit of $10 \%$ and $B$ sells it to $C$ at a profit of $20 \%$. Find out the resultant profit percentage.

In a certain store, the profit is $320 \%$ of the cost. If the cost increases by $25 \%$ but the selling price remains constant, approximately what percentage of the selling price is the profit?

The ratio of the cost price and the selling price is $4: 5$. The profit percent is

$A$ person bought an article for $Rs. 240$. For how much should he sell it so as to lose $20\%$?

$10 \%$ discount and then $20 \%$ discount in succession is equivalent to a total discount of $... \%$.