Question 803344: How many liters of pure alcohol must be added to 20 liters of 20 percent solution to obtain a 80 percent solution? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! --- percent ---------------- Amount
Alcohol solution 20 ---------------- 20 liters
pure alcohol 100 ---------------- x liters
Mixture 80 ---------------- 20 + x liters
20 * 20 + 100 x = 80 ( 20 + x )
400 + 100 x = 1600 + 80 x
100 x -80 x = -400 + 1600
20 x = 1200
/ 20
x = 60 liters pure alcohol
