How many liters of each of a 15% acid solution and a 65% acid solution must be used to produce 80 liter of 60% acid solution?

8 liters of 15% solution and 72 liters of 65% solution

Step-by-step explanation:

If x is the liters of 15% solution, and y is the liters of 65% solution, then:

x + y = 80

0.15x + 0.65y = 0.60 (80)

Solve the system of equations with substitution or elimination. Using substitution:

0.15x + 0.65 (80 - x) = 0.60 (80)

0.15x + 52 - 0.65x = 48

4 = 0.5x

x = 8

y = 72

You need 8 liters of 15% solution and 72 liters of 65% solution.