Question 922901
Ten liters of 40% acid solution is made by mixing a 20% and a 50% solution.
How much of the 20% solution is required to get the specified concentration?
:
let x = amt of 20% solution required
the resulting amt is to be 10 lt, therefore
(10-x) = amt of 50% solution
:
Write an amt of acid equation, using the decimal equiv of per cents
.2x + .5(10-x) = .4(10)
.2x + 5 - .5x = 4
.2x - .5x = 4 - 5
-.3x = -1
x = -1/-.3
x = +3{{{1/3}}} liters of the 20% solution