A 20% acid solution is mixed with 20 liters of a 45% acid solution. How much of a 30% acid solution will result?

50 liters

Step-by-step explanation:

If x is the volume of 20% acid, then:

x (0.20) + 20 (0.45) = (x + 20) (0.30)

0.2x + 9 = 0.3x + 6

3 = 0.1x

x = 30

30 liters of 20% acid are needed, so there will be a total of 50 liters of 30% acid.