A driver just filled the car's gas tank with 27 liters of gasohol, a mixture consisting of 5% ethanol and 95% gasoline. If the car runs best on a mixture consisting of 10% ethanol and 90% gasoline, how many liters of ethanol must be added into the gas tank for the car to achieve optimum performance?
Choose the correct choice from the following choices:
A) 1.2	B) 1.5	C) 1.8	D) 2.1	E) 2.4

Rationale: let x be the number of liters of ethanol added to the gas tank . 0.05 ( 27 ) + x = 0.1 ( 27 + x ) 0.9 x = 2.7 - 1.35 = 1.35 x = 1.5 liters the answer is b .
Answer: B