If the lab technician needs 30 liters of a 25% acid solution, how many liters of the 10% and 30% acid solution should she mix to get what she needs?
+23246 Let x = liters of the 10% solution.
Then 30 - x = liters of the 30% solution
(percentage) · (amount) + (percentage) · (amount) = (final percentage) · (final amount)
0.10 · x + 0.30 · (30 - x) = 0.25 · 30
0.10x + 9.00 - 0.30x = 7.50
9.00 - 0.20x = 7.50
- 0.20x = -1.50
x = 7.5 liters of the 10% solution
30 - x = 22.5 liters of the 30% solution
