Problem Solving

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Problem Solving

by akash singhal » Fri May 15, 2015 3:23 am
If x > y^2 > z^4, which of the following statements could be true?

1. x>y>z
2. z>y>x
3. x>z>y

A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
E. 1,2 and 3


Try it a nice question...
Answer after your explanation...

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by akash singhal » Fri May 15, 2015 3:34 am
Sorry i just saw that this question was posted before by somebody... if u have solved it ignore it

Thanks....


Is there any process to solve such inequalities or just we have to put the value and check????
If their is a process do share???

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by GMATGuruNY » Fri May 15, 2015 4:24 am
akash singhal wrote:If x > y^2 > z^4, which of the following statements could be true?

1. x>y>z
2. z>y>x
3. x>z>y

A. 1 only
B. 1 and 2 only
C. 1 and 3 only
D. 2 and 3 only
E. 1,2 and 3

.
Constraint: x > y² > z�

Statement I: x > y > z
To make x > y > x and x > z�, let x be a large integer and z be a small integer.
Case 1: x=10, y=2 and z=1
In this case, x > y² > z� and x > y > z.
Since statement I is possible, eliminate D.

Statement III: x > z > y
In Case 1, changing the signs of y and z will make z > y.
Case 2: x=10, z=-1 and y=-2
In this case, x > y² > z� and x > z > y.
Since statement III is possible, eliminate A and B.

Statement II: z > y > x
To make z > y > x and x > z�, let x and z be positive fractions, since a positive fraction raised to a power greater than 1 gets SMALLER.
Case 3: z=1/2, y=1/3, x=1/4
In this case, x > y² > z� and z > y > x.
Since statement II is possible, eliminate C.

The correct answer is E.
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by Brent@GMATPrepNow » Fri May 15, 2015 7:48 am
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

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