is y-x positive?

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by papgust » Fri Jan 08, 2010 1:21 am
The operator sign in the question stem is not clear. Can you check that?

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by bhumika.k.shah » Fri Jan 08, 2010 1:27 am
papgust wrote:The operator sign in the question stem is not clear. Can you check that?
done!

is y-x positive ?

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by papgust » Fri Jan 08, 2010 1:41 am
Is y-x +ve?

1. y > 0

We don't know anything about x. If x is -ve, y-x is positive. If x is +ve, y-x COULD be -ve or +ve.
Insufficient.

2. x = 1 - y
x + y = 1

If x = -1, y = 2, x+y=1, y-x is +ve. YES
If x = 3, y = -2, x+y=1, y-x is -ve. NO
Insufficient

Combined,
y > 0 from I.

Using Statement II,
Let y=2, x=-1, y-x is +ve. YES
Let y=1/2, x=1/2, x+y=1 BUT y-x is 0. NO.
Insufficient

Remember we are not told whether x and y are integers. Otherwise, the answer would be C.

Therefore, E.