The pilot of a small aircraft with a 40-gallon fuel tank wants to fly to Cleveland, which is 520 miles away. The pilot recognizes that the current engine, which can fly only 8 miles per gallon, will not get him there. By how many miles per gallon must the aircraft’s fuel efficiency be improved to make the flight to Cleveland possible?
Options.
A) 5	B) 4	C) 12	D) 40	E) 160
Actual miles/gallon is = 520/40= 
<gadget id="calculator">520/40</gadget>
<output>13</output>
13 miles/gallon.   Current engine miles/gallon is 8 miles/gallon.   Additional 5 miles/gallon is required to match the actual mileage.   IMO option 5.
<result>A</result>
The pilot of a small aircraft with a 40-gallon fuel tank wants to fly to Cleveland, which is 520 miles away. The pilot recognizes that the current engine, which can fly only 8 miles per gallon, will not get him there. By how many miles per gallon must the aircraft’s fuel efficiency be improved to make the flight to Cleveland possible?