Is |X-1| < 1 ?
1) (x-1)^2 <= 1
2) x^2 - 1 > 0
Source: 2008 GMAT Club
OA:E
I think its [spoiler]B)[/spoiler](The reason being if its equal to or greater we can answer the question with a definite NO which makes it SUFFICIENT)
Comments/feedback welcome!
ABSOLUTE VALUE YES/NO DS
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Is |X-1| < 1 ?cramya wrote:Is |X-1| < 1 ?
1) (x-1)^2 <= 1
2) x^2 - 1 > 0
Source: 2008 GMAT Club
OA:E
I think its [spoiler]B)[/spoiler](The reason being if its equal to or greater we can answer the question with a definite NO which makes it SUFFICIENT)
Comments/feedback welcome!
When will this be true?
Well, if x is between 0 and 2, we'll get a yes.
Every other value will give us a no.
(1) (x-1)^2 <= 1
x = 1.5 fits this rule and gives us a "yes" answer.
x = 2 fits this rule and gives us a "no" answer.
Insufficient!
(2) x^2 - 1 > 0
x = 1.5 fits this rule and gives us a "yes" answer.
x = 2 fits this rule and gives us a "no" answer.
Insufficient.
Together:
we can still choose both 1.5 and 2, so we can still get both a "yes" and a "no"... choose (E), not enough information.
Remember, we don't have to pick integers!
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Stmt II
I simplified
x^2>1
|x|>1
x>1 x<-1
Considered just integers which led me to B).
So going back to my question if x was given to be an integer would B) be the right choice?
Thanks Stuart!!!!!!
This is hurting me from time and again! I am thinking this post hopefully reinstills the consideration of non integers in a DS when no info on x is givenRemember, we don't have to pick integers!
Stmt II
I simplified
x^2>1
|x|>1
x>1 x<-1
Considered just integers which led me to B).
So going back to my question if x was given to be an integer would B) be the right choice?
Thanks Stuart!!!!!!
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- Location: Pittsburgh
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Cramya ,Please see if this works
From 1 x^2 -2x+1 <= 1
x^2 -2x<=0
x^2<= 2x-- A
Not sufficient
From 2 x^2>1 => -x^2 < -1---B
Not sufficient
Add A and B => 0<=2x-1
2x>=1
x>=1/2
X=1/2 will satisfy the question, X=3 won't ..
So E
From 1 x^2 -2x+1 <= 1
x^2 -2x<=0
x^2<= 2x-- A
Not sufficient
From 2 x^2>1 => -x^2 < -1---B
Not sufficient
Add A and B => 0<=2x-1
2x>=1
x>=1/2
X=1/2 will satisfy the question, X=3 won't ..
So E