j_shreyans wrote:Guys ,
x,y&z are nonzero numbers is (x)(y+z)>0
1) |x+y|=|x|+|y|
2) |z+y|=|y|+|z|
Question stem, rephrased:
Are x and y+z the SAME SIGN?
Statement 1 offers no information about z and thus is INSUFFICIENT.
Statement 2 offers no information about x and thus is INSUFFICIENT.
To determine whether the two statements combined are sufficient, test the following combinations in each statement:
1, 1
-1, 1
1, -1
-1, -1
Statement 1: |x+y|=|x|+|y|
|1+1|=|1|+|1| --> 2=2
|-1+1|=|-1|+|1| --> 0=2
|1+(-1)|=|1|+|-1| --> 0=2
|-1+(-1)|=|-1|+|-1| --> 2=2
The cases in red indicate that x and y must be the same sign.
By extension, statement 2 -- |z+y|=|y|+|z| -- implies that y and z must be the same sign.
Thus:
The two statements combined imply that x, y and z are all the same sign.
SUFFICIENT.
The correct answer is
C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at
[email protected].
Student Review #1
Student Review #2
Student Review #3