When the price of an article was reduced by 40% its sale increased by 80%. What was the net effect on the sale? Pick.
A) 8 % increase	B) 4 % decrease	C) 6 % 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 40 % , the new price is 0.6 p . if we increase the number sold by 80 % , the new number sold is 1.8 n . so the new revenue is ( 0.6 p ) ( 1.8 n ) = 1.08 np , which is 1.08 times the old revenue , so is 8 % greater . answer : a"
Answer: A