Given that total volume of the solution = 12 quarts
Let volume of water added = x quarts
Then volume of 30% vinegar = (12-x) quarts
Given that x quarts of 0% water is mixed with (12-x)quarts of 30% vinegar to obtain 12 quarts of 25% solution
So we can write equation as:
[0% of x] + [30% of (12-x)] = [25% of 12]
or 0x + 0.30(12-x) = 0.25*12
or 0 + 3.6-0.30x = 3
or -0.30x = 3-3.6
or -0.30x = -0.6
x=2
Hence answer will be 2 quarts of water.
