$20 \%$ loss on selling price is what per cent loss on the cost price? (in $\%$)

If a discount of $10 \%$ is given on the marked price of a radio,the gain is $20 \%$. If the discount is increased to $20 \%$,the gain is......$\%$

If $11$ mangoes are bought for $Rs. 10$ and sold at $10$ for $Rs. 11$,what is the gain or loss percentage (in $\%$)?

$A$ man bought apples at the rate of $6$ for $Rs. 20$ and sold them at $4$ for $Rs. 16$. His estimated profit $\%$ is

The ratio between the selling price and the cost price of an article is $7:5$. What is the ratio between the profit and the cost price of that article?

If the selling price of $\frac{2}{3}$ of a certain quantity of milk is equal to the cost price of the whole quantity of milk,then what will be the gain percent in this transaction?