$A$ man buys an article for $10 \%$ less than its value and sells it for $10 \%$ more than its value. His gain or loss percent is

The difference between successive discounts of $40\%$ followed by $30\%$ and $45\%$ followed by $20\%$ on the marked price of an article is $Rs. 12$. The marked price of the article is (in $Rs.$)

$A$ man gains $15 \%$ by selling a calculator for a certain price. If he sells it at triple the price,then what will be the profit percentage (in $\%$)?

Aditya bought a scooter for a certain sum of money. He spent $15 \%$ of the cost price on repairs and sold it for a profit of $Rs. 1104$. What did he spend on repairs if the profit he earned was $20 \%$?

$APD$ printed $3000$ copies of 'Career Power' at a cost of $Rs. 240000$. It gave $500$ copies free to different philanthropic institutions. It allowed a discount of $25\%$ on the published price and gave one copy free for every $25$ copies bought at a time. It was able to sell all the copies in this manner. If the published price is $Rs. 325$,then what is its overall gain or loss percentage in the whole transaction?

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