Question 371376
solution A 30% acid, solution B is 100% acid.  How many liters should be combined to make 28 liters of a solution that is 50%acid?

X + Y = 28
30% 100%=50%
30x 100y 50% of 24 liters    <<this is the graph/chart i compiled from book.
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x = amount of solution A
y = amount of B
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x + y = 28 --> y = 28-x
0.3x + y = 0.5*28 = 14
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y = 28-x
0.3x + 28-x = 14
-0.7x = -14
x = 20 liters
y = 8 liters
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I would have used A and B instead of x and y, but the answer is the same.