The correct answer is E
Explanation
The car service uses a total of g gallons of gasoline per week, and each of the cars uses the same amount of gasoline, so each of the c cars uses g /c gallons of gasoline per week. Therefore, 5 of the cars use a total of (5g)/c gallons per week. It follows that 5 of the cars use (2) ((5g) /c) =(10g) / c gallons of gasoline in 2 weeks.