x>y>z

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x>y>z

by 750+ » Sun Jun 26, 2016 8:23 pm
Can someone please provide a solution
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by Brent@GMATPrepNow » Sun Jun 26, 2016 8:26 pm
If x > y² > z�, 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 > y² > z�, then we'll keep that statement.

Statement I. x > y > z
If x = 2, y = 1, and z = 0, then x > y² > z�
KEEP statement I

Statement II. z > y > x
If x = 1/4, y = 1/3, and z = 1/2, then x > y² > z�
KEEP statement II

Statement III. x > z > y
If x = 2, y = -1, and z = 0, then x > y² > z�
KEEP statement III

Answer: E

Cheers,
Brent
Last edited by Brent@GMATPrepNow on Sun Jun 26, 2016 8:27 pm, edited 1 time in total.
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by Brent@GMATPrepNow » Sun Jun 26, 2016 8:27 pm
Here's a similar question: https://qa.www.beatthegmat.com/0-888-sq- ... 74282.html

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by 800_or_bust » Mon Jun 27, 2016 7:36 am
750+ wrote:Can someone please provide a solution
(1) Obviously could be true.
(2) Could be true. Pick z = 2, y = 3, and x = 4, then x = 4, y^2 = 9, and z^4 = 16. Both inequalities hold.
(3) Could be true. We already proved z could be less than y in (2) above. Just use x = 0, and both inequalities still hold.

Answer: e
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by [email protected] » Mon Jun 27, 2016 9:12 am
Hi 750+,

Brent has provided a great explanation that TESTS VALUES, so I won't rehash that here.

Instead, I'm going to point out the Number Properties that this question is based on. These are "math rules" that are worth knowing, as Number Properties show up on a variety of questions in the Quant section:

1) ANY positive or negative number, when raised to an EVEN INTEGER power, becomes positive.
2) 0, raised to ANY power, is still 0.
3) Positive fractions, when raised to a POSITIVE power GREATER THAN 1, become SMALLER

Number Properties tend to show up in Roman Numeral questions and in DS questions, so keep an eye out for them (and learn them) during your studies.

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