When the price of an article was reduced by 15% its sale increased by 80%. What was the net effect on the sale?
Select the correct option:
A) 44% increase  B) 44% decrease  C) 53% increase  D) 66% increase  E) 66% decrease
if n items are sold for $p each, revenue is $np. If we reduce the price by 15%, the new price is 0.85p. If we increase the number sold by 80%, the new number sold is 1.8n. So the new revenue is (0.85p)(1.8n) = 1.53np, which is 1.53 times the old revenue, so is 53% greater.   ANSWER:53% increase
<result>C</result>
When the price of an article was reduced by 15% its sale increased by 80%. What was the net effect on the sale?