The question is incomplete, here is the complete question:
In the lab, keith has two solutions that contain alcohol and is mixing them with each other. Solution A is 20 % alcohol and Solution B is 6 % alcohol. He uses 400 milliliters of Solution A. How many milliliters of Solution B does he use, if the resulting mixture is a 12% alcohol solution?
<u>Answer:</u> The volume of solution B used is 533.3 mL
<u>Explanation:</u>
We are given:
Volume percent of alcohol in solution A = 20 %
Volume percent of alcohol in solution B = 6 %
Let the volume of solution B used be 'x' mL
Volume of solution A used in the mixture = 400 mL
Total volume of the mixture = (400 + x) mL
Calculating the volume of solution B used:
Hence, the volume of solution B used is 533.3 mL