I came across this problem, just wanted to know if there is a better way of solving this problem then the approach I had:
1. A car traveled 462 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?
m = miles traveled per gallon AND g = no. of gallons
mg = 462 (I)
(m-6)g = 336 (II)
Solving eq I and and II
We get, (Solving I and II consumed lot of time)
m = 336 / 21
Now miles/ gallon in city is
336 / 21 â€“ 6 = 16
Here is how I would set up the equation.
mpg(highway) - mpg(city) = 6
Assuming n = full tank gallon of this car
mpg(highway) = 462(mile) / n (gallon) = 462/n mpg
mpg(city) = 336 (mile) / n (gallon) = 336/n mpg
(462/n) - (336/n) = 6
462 - 336 = 6n
n = 126/6 = 21 gallon
mpg(city) = 336/21 = 16 mpg.