We have 40 liters of 70% alcohol How much 30% must we add to make 40% alcohol? .70 * 40 + .30x = .40 * (40 + x) 28 + .30x = 16 + .40x
12 = .10 x x = 120 liters of 30% must be added ********************************************* Double-Check 40 ltrs .70 alcohol = 28 liters alcohol 12 water 120 ltrs. .30 alcohol = 36 ltrs. alcohol 84 water
adding both we get 64 ltrs. alcohol 96 ltrs. water 160 liters total 64 / 160 = .40 or 40% alcohol solution correct!!! Source:1728.com/mixture.htm
