Is |x| = y -z?
1) x+y = z
2) x < 0
[spoiler]ANS:C[/spoiler]
This problem is from OG 11. Can some one explain me the problem and how to deal with absolute no questions in general?
Jerry.
Absolute DS
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Hi,
From(1): x+y=z => x=z-y
So, |x| = |z-y|
So, |x| = z-y if x>0
& |x| = y-z if x<0
Insufficient
From(2):
x<0. No info about the relation between x,y,z
Insufficient
Both(1)&(2): x<0
So, from(1) we can say |x| = y-z
Sufficient
Hence, C
From(1): x+y=z => x=z-y
So, |x| = |z-y|
So, |x| = z-y if x>0
& |x| = y-z if x<0
Insufficient
From(2):
x<0. No info about the relation between x,y,z
Insufficient
Both(1)&(2): x<0
So, from(1) we can say |x| = y-z
Sufficient
Hence, C
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Things are not what they appear to be... nor are they otherwise
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|x|=y-z??
a) x+y=z
x=z-y
|X| = |z-y| = y-z only when y>=z
= z-y when z>y
insufficient
b)x<0 insufficient
a&b) x<0
x+y=z -> z<y
thus |x| = y-z
Sufficient
IMO C
a) x+y=z
x=z-y
|X| = |z-y| = y-z only when y>=z
= z-y when z>y
insufficient
b)x<0 insufficient
a&b) x<0
x+y=z -> z<y
thus |x| = y-z
Sufficient
IMO C
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Cans!!
![Wink ;)](./images/smilies/wink.png)
Contact me about long distance tutoring!
[email protected]
Cans!!
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|x| = y -z?
This gives two equations when x >=0 0 x = y-z => eq 1 and when x< 0 -x = y-z i.e x = z-y => eq 2
1 : X+Y = Z first take +ve x x=1, y=2 and z=3 when we substitute in eq 1 we get False and when we substitute in eq 2 we get True. Since we get both true and false this is insufficient.
2: By itself it doesn't give any relation among x,y and z so Insuff
Now combining both check for only negative values of X So we have to take some values and substitute only in EQ 2 since we know that x < 0
Now we take -1,3, 2 -1 = 2-3
-1 = -1
Take only more example just to be sure
-5 7 2 -5 = 2-7
-5 = 5
So Sufficient answer is C
This gives two equations when x >=0 0 x = y-z => eq 1 and when x< 0 -x = y-z i.e x = z-y => eq 2
1 : X+Y = Z first take +ve x x=1, y=2 and z=3 when we substitute in eq 1 we get False and when we substitute in eq 2 we get True. Since we get both true and false this is insufficient.
2: By itself it doesn't give any relation among x,y and z so Insuff
Now combining both check for only negative values of X So we have to take some values and substitute only in EQ 2 since we know that x < 0
Now we take -1,3, 2 -1 = 2-3
-1 = -1
Take only more example just to be sure
-5 7 2 -5 = 2-7
-5 = 5
So Sufficient answer is C