Mixture problem, whats the best approach?? GMAT Prep

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Three Grades of milk are 1%, 2% and 3% fat by volume. If x gallons of 1 % grade, Y gallons of 2% and Z gallons of 3% grade are mixed to X+Y+Z galllons of 1.5 % grade. What is X in terms of Y and Z

a) y+3z

b)(Y+Z)/4

c)2Y+3Z

d)3Y+Z

e)3Y+4.5 Z

Solutions???

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by blitz28 » Tue Feb 03, 2009 8:13 pm
Thanks Guys,

Got it the moment I posted...

Guess BTG is magic mantra ;-))

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by hrishikesh05 » Fri Feb 06, 2009 1:30 am
Well the answer is A

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by Uri » Fri Feb 06, 2009 5:45 am
blitz28 wrote:Thanks Guys,

Got it the moment I posted...

Guess BTG is magic mantra ;-))
What is "BTG" :?:

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by blitz28 » Fri Feb 06, 2009 8:22 am
:-)

BTG is where u r operating

:lol: Beat the GMAT!!!

:D

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by mdavis » Fri Feb 06, 2009 9:17 am
Would someone mind posting a solution? Thanks!

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blitz28 wrote:Three Grades of milk are 1%, 2% and 3% fat by volume. If x gallons of 1 % grade, Y gallons of 2% and Z gallons of 3% grade are mixed to X+Y+Z galllons of 1.5 % grade. What is X in terms of Y and Z

a) y+3z

b)(Y+Z)/4

c)2Y+3Z

d)3Y+Z

e)3Y+4.5 Z

Solutions???
.01(x) + .02(y) + .03(z) = .015(x+y+z)

multiply by 200 to clear decimals:

2x + 4y + 6z = 3(x+y+z)
2x + 4y + 6z = 3x + 3y + 3z

separate the "x"s from the "y"s and "z"s:

y + 3z = x

choose (A)!
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