A cool little thing I translated from a Chinese comic:
Seller: 100 pounds of bananas for $100!
Buyer: I’ll buy your bananas but it’s way to expensive. How about I just buy the contents of the bananas and not buy the peels?
Seller: Well for every 10 pounds of bananas, there are 8 pounds of edible parts, and 2 pounds of peels.
Buyer: Okay then - I’ll only pay for the contents and not the peels. For every pound I’ll give you 80 cents.
Seller: Um… okay.
Buyer: Then there are 80 pounds of it and I’ll pay 80 cents for every pound. 80 * 0.8 = $64. Deal?