A driver just filled the car's gas tank with 54 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.
A) 1.5
B) 2
C) 2.4
D) 2.7
E) 3
Let x be the number of liters of ethanol added to the gas tank.   0.05(54) + x = 0.1(54+x)   0.9x = 5.4 - 2.7= 
<gadget id="calculator">5.4 - 2.7</gadget>
<output>2.7</output>
2.7   x= 3 liters   The answer is 3.
<result>E</result>
A driver just filled the car's gas tank with 54 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?