Muzali,muzali wrote:Would appreciate a detailed explanation.
You can rephrase this question as:
Is X<3
St 1)
X is not 3. Insuf
2) -x > 0 since absolute is +
x<0
well if x is less than 0, it is less than 3 so SUF
I would go with B.
another one
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Source: Beat The GMAT — Data Sufficiency |
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logitech
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You can rephrase this question as:
Is X<3
St 1)
X is not 3. Insuf
2) -x > 0 since absolute is +
x<0
well if x is less than 0, it is less than 3 so SUF
I would go with B.
LGTCH
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"DON'T LET ANYONE STEAL YOUR DREAM!"
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"DON'T LET ANYONE STEAL YOUR DREAM!"
wait doesn't root(x-3)^2 imply |x-3| rather than just x-3???logitech wrote:Muzali,muzali wrote:Would appreciate a detailed explanation.
You can rephrase this question as:
Is X<3
St 1)
X is not 3. Insuf
2) -x > 0 since absolute is +
x<0
well if x is less than 0, it is less than 3 so SUF
I would go with B.
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austin
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Is x-3 = 3-x????
or is x = 3???
1. x!= 3 Sufficient
2. -x|x| > 0
|x| is always positive. If -x|x| > 0 then x has to be negative.
eg. x = -3; -(-3)|-3| >0.. so x cannot be 3..
D
or is x = 3???
1. x!= 3 Sufficient
2. -x|x| > 0
|x| is always positive. If -x|x| > 0 then x has to be negative.
eg. x = -3; -(-3)|-3| >0.. so x cannot be 3..
D
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logitech
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Yes
root(x-3)^2 imply |x-3|
X>3 it is : X-3
X<3 it is : 3-X
so The question asks whether x is less than 3. And it is B!
root(x-3)^2 imply |x-3|
X>3 it is : X-3
X<3 it is : 3-X
so The question asks whether x is less than 3. And it is B!
LGTCH
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"DON'T LET ANYONE STEAL YOUR DREAM!"
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"DON'T LET ANYONE STEAL YOUR DREAM!"
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sudhir3127
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muzali wrote:Would appreciate a detailed explanation.
NOTE : We should know that a square root cannot be negative in GMAT . Our aim is to prove that LHS = RHS . we have to solve the equation to get a value
Statement 1
Nothing is told whether X is postive/negative .thus insufficent .
Statment 2.
-Xmod(x) >0
For the above to be true X has to be negative .
thus when X is negative
sqrt [(x-3)^2] = 3-x
put X = -4
sqrt( 49) = 3-(-4)
7 =7
this is possible only when X<0 and B tells us that,
Hope its clear. do let me know if u have any doubts..
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logitech
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Guys do not leave this question BEFORE you understand why B is the correct answer. Know your absolute values!
LGTCH
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"DON'T LET ANYONE STEAL YOUR DREAM!"
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"DON'T LET ANYONE STEAL YOUR DREAM!"
Not so sure of ans. B
Given sqrt((x-3)^2) you know that (x-3)^2 is positive so you can go ahead and simplify and then equate to the other side.
i.e (x-3)^(2*1/2) = 3-x --> rephrases to be is x = 3?
Ans option A, in my opinion should be correct.
Given sqrt((x-3)^2) you know that (x-3)^2 is positive so you can go ahead and simplify and then equate to the other side.
i.e (x-3)^(2*1/2) = 3-x --> rephrases to be is x = 3?
Ans option A, in my opinion should be correct.
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pbanavara
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I guess solving the equation gives only one of the possible values, doesn't necessarily mean that's the only value. x=3 solves the equation if you substitute the value back but so does x=-4. X being negative ensures that the equation is always true for negative values.dzinyo00 wrote:Not so sure of ans. B
Given sqrt((x-3)^2) you know that (x-3)^2 is positive so you can go ahead and simplify and then equate to the other side.
i.e (x-3)^(2*1/2) = 3-x --> rephrases to be is x = 3?
Ans option A, in my opinion should be correct.
Hope this helps.
- pradeep
