First, you would make them have common denominators 4/5 (12/12) is 48/60 7/12 (5/55 is 35/60 Second, you want to find the difference 48-35=13 So from that, I would assume that the difference between the two is 13/60
if you are multiplying by 5, then the blue needs to be 25 quarts and the yellow needs to be 15 quarts not 9. If you are multiplying by 3 then it would be 9 quarts yellow and 15 quarts blue. hope this helps :)