Final answer:
To create a 40% acid solution from 50 ounces of pure acid, 75 ounces of pure water are needed, which is not listed among the provided options.
Step-by-step explanation:
The question asks how many ounces of pure water must be added to 50 ounces of pure acid to make a solution that is 40% acid. To solve this, we set up a proportion where the amount of acid remains constant, and the total weight of the solution increases with the addition of water. The relation can be expressed as:
Acid percentage (before mixing) = Acid percentage (after mixing)
100% (50 ounces) = 40% (50 ounces + x ounces)
Now, we solve for x, where x is the amount of water to add:
50 = 0.4 (50 + x)
50 = 20 + 0.4x
30 = 0.4x
x = 75
To make a solution that is 40% acid by adding water to 50 ounces of pure acid, we must add 75 ounces of water. This means the initial understanding of the question was incorrect, as none of the given options (A, B, C, D) indicate 75 ounces.