A certain car uses one gallon of gasoline every 38 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?  Select
A) 15%  B) 20%  C) 22.5%  D) 45%  E) 50%
4 miles on the highway = 4/38 gallons;   4 miles in the city = 4/20 gallons;   Total = 4/38 + 4/20 = 29/95 gallons.   8 miles on the highway = 8/38 gallons .   The % change = (29/95 - 8/38)/(8/38) = 0.45.   Answer: 45%.
<result>D</result>
A certain car uses one gallon of gasoline every 38 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?