Question 252193:  I need help on setting up this word problem in a chart. I don't know which one is x and which is y. I think one of the equations is x+y=10, but I don't know what the other is.
 
For extremely cold temperatures, an automobile manufacturer recommends that a 60% antifreeze and 40% water mix be used in the cooling system of a car. How many quarts of pure (100%) antifreeze and 50% antifreeze and 50% water mix should be combined to make 10 quarts of 60% antifreeze and 40% water mix? 
 Answer by drk(1908)      (Show Source): 
You can  put this solution on YOUR website! This question is a bit tricky in that they give you water and antifreeze. Just focus on the antifreeze numbers. Here is the table. "BIG SPACE" will mean leave a big space between the information in the columns. Your basic idea is correct, but I generally try to get one variable.
 
        %      BIG SPACE                   L      BIG SPACE                   %L 
A     100  BIG SPACE                  X       BIG SPACE                 100X 
B     50    BIG SPACE                 10-X  BIG SPACE                  500 - 50X 
MIX 60    BIG SPACE                10       BIG SPACE                 600.
 
From this table, we have one formula:
 
100X + 500 - 50X = 600. Solving for X, we get X = 2.
 
You need 2Q of pure antifreeze and 8 Q of the 50% antifreeze. 
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