Maria needs to mix a 20% acid solution with a 60% acid solution to create 100 milliliters of a 56% solution. How many milliliters of each solution must Maria use?
milliliters of 20% solution and
milliliters of 60% solution.
Let x be the number of milliliters of the 20% acid solution.
Then, 100 - x is the number of milliliters of the 60% acid solution.
The amount of acid from the 20% solution is 0.20x.
The amount of acid from the 60% solution is 0.60(100 - x).
The total amount of acid in the final solution is 0.56(100).
0.20x + 0.60(100 - x) = 0.56(100)
0.20x + 60 - 0.60x = 56
0.40x = 4
x = 4/0.40
x = 10
Therefore, Maria needs to use 10 milliliters of the 20% solution and 100 - 10 = <<100-10=90>>90 milliliters of the 60% solution. Answer: \boxed{10,90}.