A solution of 67% herbicide is to be mixed with a solution of 46% herbicide to form 42 liters of a 55% solution. How much of the 67% solution must she use?

Answer 1

Let S=amt of 67% and F=amt of 46%

S+F=42

.67S+.46F = .55*42

The solution is numerically messy, but substitute S=42-F into the 2nd equation

.67(42-F) +.46F = .55*42

.21F = ...12*42

F=24

and S= 18