Question

Bruce wants to make 50 ml of an alcohol solution with a 12% concentration. He has a 10% alcohol solution and a 15% alcohol solution. Which equation can Bruce use to determine how much of the 10% alcohol solution he should use?

A.0.10x + 0.15(50 – x) = 50 + 0.12
B.0.10x + 0.15(50 – x) = 0.12(50)
C.0.10x + 0.15(50 – x) = 50 + 0.12 + 0.12(50)
D.(0.10x)(0.15)(50 – x) = 0.12(50)

Answer 1

B

Explanation:

Answer 2

B
Here, x is the volume of the 10ml solution. Multiplying it by its concentration gives the amount of alcohol in it. 50 is the total volume of the 12% solution so (50 - x) gives the volume of the 15% solution. Multiplying this by the concentration gives the amount of alcohol in it. The sum of these amounts of alcohols is equivalent to the amount of alcohol in the 12% solution which is given by the product of its volume and concentration.