How would I set up "A solution is 30% chlorine and another solution is 60% chlorine. How many liters of each solutiom should you use to make 120 liters of a solution that is 40% chlorine?"
+130511 Let the number of litres of 30% concentration = x
And since we have 120 litres as a final amount, then the number of litres of the 60% solution is just
(120-x). So we have
.30x + .60(120-x) = .40(120)
.30x + 72 - 60x = 48 Subtract 72 from both sides and simplify the left side
-.30x = -24
.30x = 24 Divide both sides by .30
x = 80 And that's the number of litres of the 30% solution we need
And (120 - x) = (120 - 80) = 40 And that's the number of litres of the 60% solution we need
+130511 Let the number of litres of 30% concentration = x
And since we have 120 litres as a final amount, then the number of litres of the 60% solution is just
(120-x). So we have
.30x + .60(120-x) = .40(120)
.30x + 72 - 60x = 48 Subtract 72 from both sides and simplify the left side
-.30x = -24
.30x = 24 Divide both sides by .30
x = 80 And that's the number of litres of the 30% solution we need
And (120 - x) = (120 - 80) = 40 And that's the number of litres of the 60% solution we need
