6 liters of a 15% salt solution are mixed with 4 liters of a 25% salt solution. What is the salt concentration of the mixture?
Answer and explanation
Correct answer: D. 19%
- Step 1: Salt in the first solution: 6 x 15% = 0.9 L; in the second: 4 x 25% = 1 L.
- Step 2: Total salt 1.9 L in 10 L gives 19%.
Answer
19%.
Why not the others: Averaging the two concentrations ignores that the volumes are different.
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