A certain car uses one gallon of gasoline every 34 miles when it travels on highway, and one gallon of gasoline every 20 miles when it travels in the city. When a car travels 4 miles on highway and 4 additional miles in the city, it uses what percent more gasoline than if it travels 8 miles on the highway?
Choose the correct option
A) 15% B) 20% C) 22.5% D) 35% E) 50%
4 miles on the highway = 4/34 gallons;   4 miles in the city = 4/20 gallons;   Total = 4/34 + 4/20 = 27/85 gallons.   8 miles on the highway = 4/17 gallons .   The % change = (27/85 - 4/17)/(4/17) = 0.35.   Answer: 35%.
<result>D</result>
A certain car uses one gallon of gasoline every 34 miles when it travels on highway, and one gallon of gasoline every 20 miles when it travels in the city. When a car travels 4 miles on highway and 4 additional miles in the city, it uses what percent more gasoline than if it travels 8 miles on the highway?