A reduction in the price of petrol by 10% enables a motorist to buy 5 gallons more for $190. Find the original price of petrol?	Pick
A) $ 11 B) $ 5 C) $ 45 D) $ 400 E) $ 4.2

Rationale: "price decreased by 10 % , so 9 / 10 times , which means that original gallons bought increased 10 / 9 times . since this increase equals to 5 gallons then 45 gallons were bought originally ( 45 * 10 / 9 = 50 - - > increase 5 gallons ) . hence original price was 190 / 45 = $ 4.2 answer : e ."
Answer: E