Monico needs to mix a 40% ethanol solution with a 60% ethanol solution to create 100 millileters of a 54% solution. How many millileters of each solution must Monico use?
If there are x ml of 40%, then there are 100-x ml of 60%, since the total is 100 ml.
So, consider the amount of ethanol. The volumes in each part must add up to the volume in the total.
.40x + .60(100-x) = .54(100)
x = 30
so, 30ml of 40%, 70ml of 60%
check:
.4*30 + .6*70 = 12+42 = 54