You can
put this solution on YOUR website!well, logically if you think this out if car B gets 1/3 the mpg that Car A gets then any gas car A uses would mean that car B would uses 3 times that amount
the way you would write this as a proportion is
27mpg*2gal=9mpg*xgal where x is gal used by car B
54=9x and

......how about that 3 times the amount of car A