Question 265884: How many gallons of 30% alcohol solution and 70% alcohol solution must be mixed to get 16 gallons of 60% solution? Answer by vksarvepalli(154) (Show Source):
You can put this solution on YOUR website! let x gallons of 30% alcohol solution be taken
it contains 0.3x gallons of alcohol
let y gallons of 70% alcohol solution be taken
it contains 0.7x gallons of alcohol
now to get 16 gallons
x+y=16 ------------------ equation 1
and to have a 60% alcohol solution
the amount of alcohol must be 60% of 16 = 9.6 gallons
so 0.3x+0.7y = 9.6 ------------- equation 2
now multiply eq.1 by 0.3 and subtract it from eq.2
we get 0.4y = 4.8
so y=12
and x=4
So 4 gallons of 30% alcohol solution and 12 gallons of 70% alcohol solution should be mixed to get 16 gallons of 60% alcohol solution.