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

The cost price of $20$ articles is the same as the selling price of $x$ articles. If the profit is $25 \%$,then the value of $x$ is:

The price of an article is raised by $30 \%$ and then two successive discounts of $10 \%$ each are allowed. Ultimately,the price of the article is

$A$ merchant buys $4000 \, kg$ of wheat,one-fifth of which he sells at a gain of $5 \%$,one-fourth at a gain of $10 \%$,one-half at a gain of $12 \%$,and the remainder at a gain of $16 \%$. If he had sold the whole at a gain of $11 \%$,he would have made $Rs. 72.80$ more. What was the cost price of the crop per $kg$? (in $Rs.$)

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

Ram purchases a chair at $Rs. 70$ and spends $Rs. 17$ on its repair and $50$ paise on cartage. If he sells the chair at $Rs. 100$,then his approximate profit percentage will be?