Alcohol Mixture

Question

If a nurse has two alcohol solutions, the first (A), a 30% alcohol solution, and the second (B), a 60% alcohol solution, but needs 10 liters of a 40% alcohol solution, how much of each of these two solutions (A & B) is needed?

Answer 1

0.3x + 0.6(10-x)=0.4*10

x=6.67 (6 2/3 mL)

10-6.67= 3.33 (3 1/3 mL)

Solution A = 6.67 mL

Solution B = 3.33 mL