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Source: — Data Sufficiency |

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by Night reader » Mon Jan 10, 2011 3:37 pm
GHong14 wrote:Image
Is x>0 and y>0

st(1) 2(x-y)=1, x-y=1/2 check points => -1-(-3/2)=1/2 both are negative, 1/4-(-1/4)=1/2 one is positive and one is negative, 3/2 - 1=1/2 both are positive. Not Sufficient
st(2) x/y >1, only possible when i) both x and y are negative or positive AND ii) x>y Not Sufficient.

Combining st(1&2), -1-(-3/2)=1/2 both are negative Canceled because x must be > y, 1/4-(-1/4)=1/2 one is positive and one is negative Canceled because both x and y are negative or positive, 3/2 - 1=1/2 both are positive Valid.

Answer C - Yes, x and y are positive.

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by Anurag@Gurome » Mon Jan 10, 2011 10:23 pm
If anyone is interested in detailed algebraic approach instead of picking numbers, Rahul has done a very good job here : https://www.beatthegmat.com/are-x-and-y- ... tml#319368
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