Absolute value of X

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Source: — Data Sufficiency |

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by cramya » Mon Feb 23, 2009 4:24 pm
Is |x| = y-z

|x| is always positive so the question is whether y-z is positive and is equal to |x|

Stmt I

x = z-y

If z<y then |x| = y-z
If z>y then |X| = z-y
If z=y then |x| = y-z and |x| = z-y

INSUFF

Stmt II

x<0

No idea about y and z so cant tell if |x| = y-z

TOGETHER:

x = z-y

Since x < 0 therefore z-y < 0

So |x| which is positive will be equal to y-z

suff

Choose C

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by x2suresh » Mon Feb 23, 2009 7:59 pm
agree with Ramya..
C

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Re: Absolute value of X

by sureshbala » Mon Feb 23, 2009 9:31 pm
fighting_cax wrote:Is |x| = y - z ?

(1) x + y = z
(2) x < 0

OA is C

Please explain.
Statement 1:

Given y-z = -x.

Now the question: Is |x| = -x. This will be true only when x < 0. But since we do not know about the sign of x from this statement, this alone is not sufficient.

Statement 2:
Given x<0. Clearly this alone is not sufficient since we do not know anything about y and z.

Combing both, we can conclude that |x|=-x i.e |x|=y-z since x<0.

Hence C