Question

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?

a.) 52%
b.) 34%
c.) 31%
d.) 48%

Explanation:

Calculate the total amount of active anesthetic

Using the Percentage Calculation knowledge point

$$ \text{Active Anesthetic} = (40 \text{ mL} \times 0.25) + (60 \text{ mL} \times 0.40) = 10 \text{ mL} + 24 \text{ mL} = 34 \text{ mL} $$

Calculate the total volume of the mixed solution

Using the Ratios and Proportions knowledge point

$$ \text{Total Volume} = 40 \text{ mL} + 60 \text{ mL} = 100 \text{ mL} $$

Determine the concentration of the mixed solution

Using the Percentage Calculation knowledge point

$$ \text{Concentration} = \frac{34 \text{ mL}}{100 \text{ mL}} \times 100\% = 34\% $$

Answer:

• a.) 52%
• b.) 34% (Correct answer)
• c.) 31%
• d.) 48%