A 3% solution of sulfuric acid was mixed with an 18% solution of sulfuric acid to produce an 8%solution. How much 3% solution and how much 18% solution were used to produce 15 L of 8% solution?
+36916 18% = x acid content = .18x
3% = 15-x acid content = .03(15-x)
.18x + .03(15.x) = .08(15)
18x + 3 (15-x) = 8(15)
15x = 75
x = 5 L of 18% 10 L of 3%
