Subject: mathqa
Question: a car traveled 340 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city . if the car traveled 6 fewer miles per gallon in the city than on the highway , how many miles per gallon did the car travel in the city ?
Option: 
A: 416
B: 220
C: 504
D: 170
Answer: C