A fruit seller bought $240$ bananas at the rate of $Rs.\, 48$ per dozen. He sells half of them at the rate of $Rs.\,5$ per banana, $\frac{1}{6}$ th of the remaining are found to be rotten. The price per banana at which he has to sell the remaining bananas to get a profit of $25 \%$ on his entire investment is (in $Rs.$)

A trader marks his goods $40 \%$ above the cost price and allows a discount of $25 \% .$ The profit he makes, is in $\%$

If a men reduces the selling price of a fan from $Rs$ $400$ to $Rs.\, 380$, his loss increases by $2 \%$. The cost price of the fan is (in $Rs.$)

A shopkeeper gains $17 \%$ after allowing a discount of $10 \%$ on the marked price of an article. Find his profit percent if the article is sold at marked price allowing no discount.

By selling $90$ pens for $Rs.\, 80$ a man loses $20 \%$. What should be the selling price (in $Rs.$) of $90$ pens for $20\%$ profit?

The cost price of an article is $80 \%$ of its marked price for sale. How much percent does the tradesman gain after allowing a discount of $12 \% ?$