Question 561179
How much pure acid must be mixed with 80 liters of 20% acid to get 90 % acid?
Let x = amount (liters) of pure acid added
then
.20(80) + x = .90(80+x)
16 + x = 72 + .90x
16 + .10x = 72
.10x = 56
x = 560 liters