Need help on this DS ques

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AnuragRatna: Senior | Next Rank: 100 Posts; Posts: 37; Joined: Fri Apr 18, 2014 2:39 am; Location: Bangalore

by AnuragRatna » Sat Jul 19, 2014 2:23 am

If x and y are integers and x<y, what is the value of x+y?
(1) xy=4

(2) |x|=|y|

A Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D EACH statement ALONE is sufficient.
E Statements (1) and (2) TOGETHER are not sufficient.

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Source: Beat The GMAT — Data Sufficiency | Sat Jul 19, 2014 2:23 am

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by GMATGuruNY » Sat Jul 19, 2014 2:47 am

I believe that the problem should read as follows:

AnuragRatna wrote:If x and y are integers and x<y, what is the value of x+y?
(1) x^y=4

(2) |x|=|y|

Statement 1: x^y = 4
Since x<y, only one case is possible:
x=-2 and y=2, with the result that x^y = (-2)Â² = 4.
Thus:
x+y = -2+2 = 0.
SUFFICIENT.

Statement 2: |x| = |y|
Since x<y, we get the following cases:
x=-2 and y=2.
x=-1 and y=1.
x=-10 and y=10.
And so on.
In every case, x+y = 0.
SUFFICIENT.

The correct answer is D.

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GMATinsight: Legendary Member; Posts: 1100; Joined: Sat May 10, 2014 11:34 pmFollowed by: 24 members; Location: New Delhi, India; Thanked: 205 times

by GMATinsight » Sat Jul 19, 2014 5:12 am

AnuragRatna wrote:If x and y are integers and x<y, what is the value of x+y?
(1) xy=4

(2) |x|=|y|

Statement 1) xy=4
x=1, y=4 then x+y = 5 or
x=-4, y=-1 then x+y = -5 or

INSUFFICIENT

Statement 2) |x|=|y|

i.e. x and y have same absolute values irrespective of their signs
but since x < y therefore
either both positive or
both negative
or x negative and y positive

Combining the two statements

Result of Statement 2 is contradicting with the inference of statement 1 therefore the question is not properly phrased.

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GMATinsight: Legendary Member; Posts: 1100; Joined: Sat May 10, 2014 11:34 pmFollowed by: 24 members; Location: New Delhi, India; Thanked: 205 times

by GMATinsight » Sat Jul 19, 2014 5:47 am

AnuragRatna wrote:
If x and y are integers and x<y, what is the value of x+y?
(1) x^y=4 (CONSIDERING THE CORRECTION TO BE DONE)

(2) |x|=|y|

Statement 1) x^y=4
i.e. x = -2 and y = 2 is the only Solution under the given constraint

therefore x+y = 0

SUFFICIENT

Statement 2) |x|=|y|

i.e. x and y have same absolute values

but since x < y therefore

X will be negative and Y will be positive

i.e. x = -y
i.e. x+y = 0

SUFFICIENT

Answer: Option D

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