GMATPrep Mixture Question

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GMATPrep Mixture Question

by GSB12 » Sun Jul 03, 2011 11:50 pm
Can someone help me understand how you end up with A in this question, I am not able to get anything remotely close to A. Detailed explanation would be much appreciated:

Image


I realize the some of this is cut off, this is the question: Three grades of Milk are 1%, 2%, and 3% fat by volume. If x gallons of the 1% grade, y gallons of the 2% grade, and z gallons of 3% grade are mixed to give x+y+z gallons of 1.5% grade, what is x in terms of y and z?
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by kevincanspain » Mon Jul 04, 2011 12:00 am
What is the volume of fat in gallons?

0.01x + 0.02y + 0.03z

but also 0.015(x + y + z)


Equate these two expressions and solve for x
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by amit2k9 » Mon Jul 04, 2011 1:32 am
x+2y+3z = 1.5(x+y+z)

-0.5x+0.5y+1.5z = 0

thus x = y +3z
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by GSB12 » Mon Jul 04, 2011 11:08 pm
Thank you both, this helps clarify.