A car traveled 448 miles per tankful of gasoline on the highway and 336 miles per tankful of ...
A car traveled 448 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?
Answer/Solution
18
Steps/Work
Let the speed in highway be h mpg and in city be c mpg.
h = c+6
h miles are covered in 1 gallon
462 miles will be covered in 462/h.
Similarly c miles are covered in 1 gallon
336 miles will be covered in 336/c.
Both should be same (as car's fuel capacity does not change with speed)
=> 336/c = 448/h
=> 336/c = 448/(c+6)
=> 336c+336*6=448c
=>c=336*6/112=18
Answer B.
h = c+6
h miles are covered in 1 gallon
462 miles will be covered in 462/h.
Similarly c miles are covered in 1 gallon
336 miles will be covered in 336/c.
Both should be same (as car's fuel capacity does not change with speed)
=> 336/c = 448/h
=> 336/c = 448/(c+6)
=> 336c+336*6=448c
=>c=336*6/112=18
Answer B.