Crazy Eddie has a key chain factory. Eddie managed to decrease the cost of manufacturing his key chains while keeping the same selling price, and thus increased the profit from the sale of each key chain from 20% of the selling price to 50% of the selling price. If the manufacturing cost is now $50, what was it before the decrease?	Choose the correct choice from the following options:
A) $ 20  B) $ 40  C) $ 50  D) $ 80  E) $ 100

Rationale: cost + profit = income ( selling price ) profit now = 0.5 x or x - 50 0.5 x = x - 50 50 = 0.5 x x = 100 $ is selling price so , profit before was 0.2 * 100 = 20 $ cost = 100 - 20 = 80 $ answer : d
Answer: D