arthematic mean of x y z , given x+y and y+z

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explaination?
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Answer?

by moonlite » Thu Sep 25, 2008 4:37 am
Is the answer E?

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Re: Answer?

by ifthyder » Thu Sep 25, 2008 5:00 am
moonlite wrote:Is the answer E?
yeah but how

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by louvre » Thu Sep 25, 2008 5:33 am
for the average you need to know x+y+z. neither statements by itself can't provide the value, and both together will lead to x+2y+z=12, not enough I suppose!

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by moonlite » Thu Sep 25, 2008 5:49 am
That's the logic i used too...3 unknows and we can't use substitue here either.