Hard question - If x>y^2>z^4, which of the following..

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If x>y^2>z^4, which of the following statements could be true?

I.x>y>z
II. z>y>x
III. x>z>y

A. I only
B. I and II only
C. I and III only
D. II and III only
E. I, II and III

OA is E. I could not find the correct answer. Please help.

Thanks for your help.

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by Brent@GMATPrepNow » Sun Sep 15, 2013 7:04 am
VyDinh wrote:If x>y^2>z^4, which of the following statements could be true?

I.x>y>z
II. z>y>x
III. x>z>y

A. I only
B. I and II only
C. I and III only
D. II and III only
E. I, II and III
If we CAN find a set of values that satisfies a statement AND yields values such that x > y^2 > z^4, then we'll keep that statement.

Statement I. x > y > z
If x = 2, y = 1, and z = 0, then x > y^2 > z^4
KEEP statement I

Statement II. z > y > x
If x = 1/4, y = 1/3, and z = 1/2, then x > y^2 > z^4
KEEP statement II

Statement III. x > z > y
If x = 2, y = -1, and z = 0, then x > y^2 > z^4
KEEP statement III

Answer: E

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Brent
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by VyDinh » Sun Sep 15, 2013 7:15 am
Thanks Brent.

Is this because the question said "could be true" so in each case, we only need to find one case that satisfies the statement?

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by Brent@GMATPrepNow » Sun Sep 15, 2013 7:22 am
VyDinh wrote:Thanks Brent.

Is this because the question said "could be true" so in each case, we only need to find one case that satisfies the statement?
Exactly.
If the question had read "MUST be true" then none of the statements would have worked.

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