Question 278773: The radiator of a car holds 16 quarts of liquid of which 8 are antifreeze. The radiator has a leak and loses 2 quarts of liquid each week. Every week 2 quarts of water are added. After 3 weeks how much antifreeze is left in the radiator?
I know the amount of the mixture is diluted each time water is poured in, so less and less antifreeze is present after each week. I am not sure how to show the amount of antifreeze left. after each week.
There are 8/16 Antifreeze and 8/16 water, but after loosing 2 quarts of antifreeze there will be 9/16 water and 7/16 of antifreeze after the water has been added. This is where I am not sure how to proceed.
Answer by vleith(2983)   (Show Source):
You can put this solution on YOUR website! Here's a hint. Instead of focusing on the percentage of quarts, focus on the total percentage.
So as you noted, after adding the water at the end of the first week, there will again be 16 quarts in the radiator. But now, instead of 50% being anitfreeze, only 7/16 or 43.75% is antifreeze.
Now let another week go by and two more quarts leak out. Now there are 14 quarts left in the radiator -- with a density of 43.75% antifreeze.
So 14*0.4375 = 6.125 quarts of antifreeze are left.
Add two more quarts of water and do the same type logic above.
Etc
Hope that helps
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