Mth 158
Your 'question form' report has been received. Scroll down through the document to see any comments I might have inserted, and my final comment at the end.
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The radiator in a certain make of car needs to contain 60 liters of 40% antifreeze. The radiator now contains 60 liters of 20% antifreeze. How many liters of this solution must be drained and replaced with 100% antifreeze to get the desired strength?
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I'm not sure how to even approach this problem and how to make it in equation form...
Let x be the quantity you are trying to find. What quantity is that?
How much water and how much antifreeze in 60 liters of 20% solution?
How much water and how much antifreeze in 60 liters of 40% solution?
If you were to drain 1 liter of the original solution, how much water and how much antifreeze would you have?
If you were to then add 1 liter of 100% solution how many liters of water and antifreeze would you have, and what would be the percent solution?
If you were to drain x liters of the original solution, how much water and how much antifreeze would you have?
If you were to then add x literx of 100% solution how many liters of water and antifreeze would you have, and what would be the percent solution?
If you answer the questions I've posed above, you might well see how to set up the equation and solve.
If not, send me your best answers to those questions, and your best attempt to solve the problem, and I'll respond with more suggestions.