a hospital staff mixed a 77% disinfectant solution with a 89% disinfectant solution.How many liters of each were used to make 72 L to a 83% disinfectant solution?
+130516 Let x be the number of liters of 77% solution
Then 72 - x is the number of liters of 89% solution .......and we have
.77x + .89 (72 - x) = .83 (72) simplify
.77x + 64.08 - .89x = 59.76
-.12x + 64.08 = 59.76 subtract 64.08 from each side
-.12x = -4.32 divide both sides by -.12
x = 36 liters of the 77% solution
72 - 36 = 36 liters of the 89% solution
