A reduction in the price of petrol by 10% enables a motorist to buy 5 gallons more for $300. Find the original price of petrol?  Choose the correct choice:
A) $ 11	B) $ 5	C) $ 45	D) $ 400	E) $ 6.6

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 300 / 45 = $ 6.6 answer : e ."
Answer: E