A certain car can travel 40 minutes on a gallon of gasoline at 60 miles per hour. If the car had started with a full tank and had 6 gallons of gasoline left in its tank at the end, then what percent of the tank was used to travel 80 miles at 60 mph? Choose the most appropriate option:	A) 15%	B) 20%	C) 25%	D) 30%	E) 40%
Total time for travelling 80 miles @ 60 mph = 80/60 = 4/3 hour = 80 minutes.   Given, the car uses 1 gallon for every 40 minutes of driving @ 60 mph. Thus in 80 minutes it will use = 2 gallons. Thus, full tank = 2+6= 
<gadget id="calculator">2+6</gadget>
<output>8</output>
8 gallons ---&gt; 2/8= 25% of the fuel used. 25% is the correct answer.
<result>C</result>
A certain car can travel 40 minutes on a gallon of gasoline at 60 miles per hour. If the car had started with a full tank and had 6 gallons of gasoline left in its tank at the end, then what percent of the tank was used to travel 80 miles at 60 mph?