6 liters of a 20% salt solution are mixed with 4 liters of a 40% salt solution. What is the salt concentration of the mixture?
Answer and explanation
Correct answer: D. 28%
- Step 1: Salt in the first solution: 6 x 20% = 1.2 L; in the second: 4 x 40% = 1.6 L.
- Step 2: Total salt 2.8 L in 10 L gives 28%.
Answer
28%.
Why not the others: Averaging the two concentrations ignores that the volumes are different.
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