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 $12 \%$?

$A$ white goods dealer pays $10 \%$ custom duty on an iPhone that costs $Rs. 25000$ in $UK$. For how much should he mark it,if he desires to make a profit of $20 \%$ after giving a discount of $25 \%$ to the buyer? (in $Rs$)

$A$ man bought $15$ mangoes for a rupee. How many mangoes were sold for a rupee so that there is a loss of $25 \% ?$

$A$ man purchases some oranges at the rate of $3$ for $₹ 40$ and the same quantity at $5$ for $₹ 60$. If he sells all the oranges at the rate of $3$ for $₹ 50$,find his gain or loss percent (to the nearest integer).

Rehaan purchased a bike for $Rs. 54,000$. He sold it at a loss of $8\%$. With that money, he again purchased another bike and sold that at a profit of $10\%$. What is his overall loss or profit?

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