$A$ shopkeeper allows a discount of $10 \%$ on the marked price of a camera. The marked price of the camera,which costs him $₹ 600$,to make a profit of $20 \%$ should be (in $₹$):

If $5 \%$ more is gained by selling an article for $Rs. 350$ than by selling it for $Rs. 340$,the cost price of the article is:

$A$ shopkeeper sold chairs at $Rs. 2139$ each after giving a $7 \%$ discount on the labelled price. Had he not given the discount, he would have earned a profit of $15 \%$ on the cost price. What was the cost price of each chair? (in $Rs.$)

If eggs are bought $12$ for $Rs. 10$ and sold at $10$ for $Rs. 12$,what is the gain or loss $\%$?

Arun marks up the computer he is selling by $20 \%$ profit and sells them at a discount of $15 \%$. Arun's net gain percent is (in $\%$)

Oil equal to $20 \%$ of the weight of groundnut is extracted in a mill. The matter left after extraction is sold as cattle feed at the rate of $Rs. 12.5$ per $kg$. The groundnuts are bought at $Rs. 20$ per $kg$ and the processing cost is $Rs. 5$ per $kg$. At what price ($Rs.$ per $kg$) should the oil be sold to earn $20 \%$ profit on total costs (Total cost $=$ cost of groundnuts and processing costs)?