Answer:
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%.