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number line
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jaganbravo
- Junior | Next Rank: 30 Posts
- Posts: 13
- Joined: Wed Feb 20, 2008 9:27 am
Well here is the ans:
1. xyz < 0 suggests only one of them is -ve.
2. xy <0 suggests x and y lies on two sides of the origin or zero.
So lets draw the number line, and add both the constraints.
|-----------X--------------------------0-----------Y---------------------------------|
Now Z has to be positive. So Z can lie between 0 and Y or beyond Y. But it cannot be beyond Y as XY will be less than XZ. Even if you revert the picture the logic remains the same. So C.
1. xyz < 0 suggests only one of them is -ve.
2. xy <0 suggests x and y lies on two sides of the origin or zero.
So lets draw the number line, and add both the constraints.
|-----------X--------------------------0-----------Y---------------------------------|
Now Z has to be positive. So Z can lie between 0 and Y or beyond Y. But it cannot be beyond Y as XY will be less than XZ. Even if you revert the picture the logic remains the same. So C.
Well here is the ans:
1. xyz < 0 suggests only one of them is -ve.
2. xy <0 suggests x and y lies on two sides of the origin or zero.
So lets draw the number line, and add both the constraints.
|-----------X--------------------------0-----------Y---------------------------------|
Now Z has to be positive. So Z can lie between 0 and Y or beyond Y. But it cannot be beyond Y as XY will be less than XZ. Even if you revert the picture the logic remains the same.
Till this point I agree with devp but ---
The answer should be E. coz in the above figure I can interchange the positions of X and Y
1. xyz < 0 suggests only one of them is -ve.
2. xy <0 suggests x and y lies on two sides of the origin or zero.
So lets draw the number line, and add both the constraints.
|-----------X--------------------------0-----------Y---------------------------------|
Now Z has to be positive. So Z can lie between 0 and Y or beyond Y. But it cannot be beyond Y as XY will be less than XZ. Even if you revert the picture the logic remains the same.
Till this point I agree with devp but ---
The answer should be E. coz in the above figure I can interchange the positions of X and Y
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netigen
- Legendary Member
- Posts: 631
- Joined: Mon Feb 18, 2008 11:57 pm
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Ans should be E
From B we know that either X or Y is negative
From A Given that X or Y is negative we know that Z is +ve
X | Y | Z
-------------
+ | - | + Z can be between X and Y or it can be on the right of X so not between X and Y
- | + | + Z can only be between X and Y
hence insufficient.
From B we know that either X or Y is negative
From A Given that X or Y is negative we know that Z is +ve
X | Y | Z
-------------
+ | - | + Z can be between X and Y or it can be on the right of X so not between X and Y
- | + | + Z can only be between X and Y
hence insufficient.
