A -liter salt solution is salt by volume. How many liters of water must evaporate for the solution to become salt?
Answer and explanation
Correct answer: D.
- Step 1: Determine the fixed volume of salt in the original solution: .
- Step 2: Let be the volume of evaporated water, making the new total solution volume liters. Set up the concentration equation: .
- Step 3: Solve for : .
Answer
.
Why not the others: divides by half; computes ; equates the added volume to the target percentage rate; computes .
Practise more Arithmetic and percents.
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