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[quote="UmanG"]Hi,
My answer is B. Explaination is as follow,
1. Y < X,
Here if both X & Y holds the same sign either positive or negative will change the above equation to |X-Y| = |X| - |Y|
And if both have oppsite signs then since Y < X it holds the equation,
|X-Y| > |X| - |Y|
It means this option gives us |X-Y| >= |X| - |Y|.
Stetement 1 alone is NOT SUFFICIENT.
2. XY<0
This equation tells us that X & Y has oppsite signs.
Now for +ve X & -ve Y
|X-(-Y)| > |X| - |(-Y)|
--> |X+Y| > |X| - |Y|-----------(A)
(clearly X+Y in either condition will grater then X-Y.)
Or for -ve X & +ve Y
|(-X)-Y| > |(-X)| - |Y|
--> |-X-Y| > |X| - |Y|
--> |X+Y| > |X| - |Y|-----------(B)
(Same as A)
Thus using stetement 2, in either condition (+ve X & -ve Y, -ve X & +ve Y)we clearly able to say that |X-Y| > |X| - |Y|.
And so stetement 2 alone is SUFFICIENT.[/quote]
My answer is B. Explaination is as follow,
1. Y < X,
Here if both X & Y holds the same sign either positive or negative will change the above equation to |X-Y| = |X| - |Y|
And if both have oppsite signs then since Y < X it holds the equation,
|X-Y| > |X| - |Y|
It means this option gives us |X-Y| >= |X| - |Y|.
Stetement 1 alone is NOT SUFFICIENT.
2. XY<0
This equation tells us that X & Y has oppsite signs.
Now for +ve X & -ve Y
|X-(-Y)| > |X| - |(-Y)|
--> |X+Y| > |X| - |Y|-----------(A)
(clearly X+Y in either condition will grater then X-Y.)
Or for -ve X & +ve Y
|(-X)-Y| > |(-X)| - |Y|
--> |-X-Y| > |X| - |Y|
--> |X+Y| > |X| - |Y|-----------(B)
(Same as A)
Thus using stetement 2, in either condition (+ve X & -ve Y, -ve X & +ve Y)we clearly able to say that |X-Y| > |X| - |Y|.
And so stetement 2 alone is SUFFICIENT.[/quote]
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Question2:
Statement1 says: y > 1/2(x+10) , in other words the question itself.
statement2: can be contradicted by picking x as 1
y = 5
(x+10)/2 would be 5.5 greater than y
so the answer is A
Statement1 says: y > 1/2(x+10) , in other words the question itself.
statement2: can be contradicted by picking x as 1
y = 5
(x+10)/2 would be 5.5 greater than y
so the answer is A
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question 3:
Z^n = 1
what is Z?
statement 1: n<> 0
if n = 2
Z could be +1 or -1
not conclusive
statement 2:
Z>0
not enough by itself.
but this statement with statement 1 means that z = 1
hence c
Z^n = 1
what is Z?
statement 1: n<> 0
if n = 2
Z could be +1 or -1
not conclusive
statement 2:
Z>0
not enough by itself.
but this statement with statement 1 means that z = 1
hence c