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Answer: BSet 9: Systems of Equations (Intermediate)
Explanation
How much 40% saline solution must be added to 30 liters of 10% saline to create a 25% solution?
A.
25 liters
B.✓ Correct
30 liters
C.
35 liters
D.
40 liters
Detailed Explanation
Choice B is correct. Choice B is the correct answer. Let = liters of 40% solution. Equation: 0.10(30) + 0.40 x = 0.25(30 + x)$3+ 0.40 x = 7.5 + 0.25 x0.15x = 4.5x = 30$$ Solution: 30 liters Verification: \frac{0.10(30) + 0.40(30)}{30 + 30} = \frac{3 + 12}{60} = \frac{15}{60} = 0.25$ ✓ Strategic Tip: Amount of solute = concentration × volume.
Key Steps:
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The correct answer is 30 liters
Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.
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