Is sqrt(x-3)^2 = 3-x ?
1. x not equal to 3
2. -x|x| >0
My approach :
Simplifying given statement -> x-3 = 3-x -> x=3
Hence, question is Is x=3? ( Am I wrong till now ? )
Option 1 : x not equal to 3.... it gives me answer as NO.
Option 2 : -x|x| > 0 means x is negative => not equal to 3.
Since, both gives me an answer E should be right.
But OA is B
Please help me understand this.[/list]
Data Sufficiency - Yes/No
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- 6983manish
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the part in boldface is wrong ;6983manish wrote:Is sqrt(x-3)^2 = 3-x ?
1. x not equal to 3
2. -x|x| >0
My approach :
Simplifying given statement -> x-3 = 3-x -> x=3
Hence, question is Is x=3? ( Am I wrong till now ? )
Option 1 : x not equal to 3.... it gives me answer as NO.
Option 2 : -x|x| > 0 means x is negative => not equal to 3.
Since, both gives me an answer E should be right.
But OA is B
Please help me understand this.[/list]
sqrt(x-3)^2 SHOULD NOT BE NEGATIVE and the question asks if it is 3-x that means 3-x >=0 i.e. x <=3
hence the question is ;
Is x <=3 ?
statement 1) INSUFF
statement 2)
for x>0
-x^2>0 not possible
for x<0
x^2 >0 true
=> x<0 i.e. x<3
SUFFICIENT
HENCE B
hope this helps..!!
- Shalabh's Quants
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i think that this problem should be simplified as6983manish wrote:Is sqrt(x-3)^2 = 3-x ?
1. x not equal to 3
2. -x|x| >0
My approach :
Simplifying given statement -> x-3 = 3-x -> x=3
Hence, question is Is x=3? ( Am I wrong till now ? )
Option 1 : x not equal to 3.... it gives me answer as NO.
Option 2 : -x|x| > 0 means x is negative => not equal to 3.
Since, both gives me an answer E should be right.
But OA is B
Please help me understand this.[/list]
=> Is |x-3| = 3-x ?
Stat. 1...
x can surely have 0 value, but it does not help in concluding |x-3| = 3-x or not. Not Suff.
Stat. 2...
by observing |x-3| = 3-x, we can say that if x takes values less than 3, then |x-3| = 3-x holds true. If x > 3, then its not.
Pl. plug in few extreme values of x such as x = 4, 3, -4 etc. in -x|x| >0, we can conclude that stat. 2 if suff.
Ans. B.
Shalabh Jain,
e-GMAT Instructor
e-GMAT Instructor