Car X averages 25.0 miles per gallon

NIKHIL BORKER

Another approach could be

X would need 1/25 gallons to cover every mile and Y would need 1/11.9~=1/12 gallons to cover every mile

After 1 mile, Y would need approx 1/12-1/25 gallons more than X

1/12-1/25 conveniently simplifies to 13/300.

If after covering 1 mile, the difference between the gas consumption of Y and X is 13/300, then after 12000 miles, it will be 12000*13/300=40*13=520

Jan 23, 2016 • Comment

Mike McGarry, Magoosh Tutor

Aug 13, 2015 • Comment