Your shopkeeper sells a special kind of coffee.

A shopkeeper sells an article, whose cost price is Rs. 400, for Rs. 462 including sales tax @ 5%. Find the profit percentage of the shopkeeper.

A shopkeeper sells an article at a certain price. What is his gain or loss percent, if by selling it at 75% ofthat price, he loses 10% ?

A shopkeeper uses a weight of 460g instead of 500g and sells the articles at the cost price. What is the profit percentage?

Osmosis is a special kind of diffusion'. Comment.