Answer:
20 ml of 15% alcohol and 30 ml of 10% alcohol should be used to create a 12% alcohol solution.
Explanation:
Since Bruce wants to make 50 ml of an alcohol solution with a 12% concentration, and he has a 10% alcohol solution and a 15% alcohol solution, to determine how much of the 10% alcohol solution he should make the following calculations:
0.9 x 15 + 0.1 x 10 = 14.5
0.7 x 15 + 0.3 x 10 = 13.5
0.5 x 15 + 0.5 x 10 = 12.5
0.4 x 15 + 0.6 x 10 = 12
50 x 0.4 = 20
Therefore, 20 ml of 15% alcohol and 30 ml of 10% alcohol should be used to create a 12% alcohol solution.