GMAT PREP I #16

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GMAT PREP I #16

by pkw209 » Thu Dec 10, 2009 5:41 pm
Hi all,

Couldn't figure this one out. Would appreciate a brief explanation. thanks!

Q) Three grades of milk are 1 percent, 2 percent and 3 percent fat by volume. If X gallons of the 1 percent grade, Y gallons of the 2 percent grade, and Z gallons of the 3 percent grade are mixed to give x + y + z gallons of a 1.5 percent grade, what is X in terms of Y and Z?

1) y + 3z

2) (y + z) / 4

3) 2y + 3z

4) 3y + z

5) 3y + 4.5z
Source: — Problem Solving |

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by okigbo » Thu Dec 10, 2009 7:12 pm
1X + 2Y + 3Z = 1.5(X+Y+Z)
1X + 2Y + 3Z = 1.5X + 1.5Y + 1.5Z

solve for x

0.5Y+1.5Z=0.5X

Y+3Z=X

Answer is A...