Solution A is 25% acid and Solution B is 40% acid. How much of each is needed to make 60 liters of a solution that is 30% acid?

To find out how much of each solution is needed, we can set up a system of equations:

Let's say x liters of Solution A is needed.
Therefore, (60 - x) liters of Solution B is needed.

The equation representing the amount of acid in Solution A is: 0.25x
The equation representing the amount of acid in Solution B is: 0.4(60 - x)

Since we want to make a 60-liter solution that is 30% acid, we can set up the equation:

0.3(60) = 0.25x + 0.4(60 - x)

Simplifying the equation gives us:

18 = 0.25x + 24 - 0.4x

Combining like terms:

0.15x = 6

Now, solve for x:

x = 6 / 0.15

x = 40

Therefore, 40 liters of Solution A (25% acid) and (60 - 40) = 20 liters of Solution B (40% acid) are needed to make a 60-liter solution that is 30% acid.