When the price of an article was reduced by 15% its sale increased by 80%. What was the net effect on the sale?  Select:
A) 44 % increase  B) 44 % decrease  C) 53 % increase  D) 66 % increase  E) 66 % decrease

Rationale: if n items are sold for $ p each , revenue is $ np . if we reduce the price by 15 % , the new price is 0.85 p . if we increase the number sold by 80 % , the new number sold is 1.8 n . so the new revenue is ( 0.85 p ) ( 1.8 n ) = 1.53 np , which is 1.53 times the old revenue , so is 53 % greater . answer : c
Answer: C