To prepare for surgery, Anne mixes an anesthetic solution using two different concentrations: 40 mL of 25% solution and 60 mL of 40% solution.

What is the concentration of the mixed solution?

34%

Step-by-step explanation:

Amount of anesthetic in the 25% solution + amount of anesthetic in the 40% solution = amount of anesthetic in the mixed solution

0.25 (40) + 0.40 (60) = x (40 + 60)

10 + 24 = 100x

x = 0.34

The concentration of the mixed solution is 34%.