That is the intentional gotcha here...
Statement 1 says xy = y^2. and you interpreted it as x = y and this particular interpretation is wrong. xy = y^2 can be true even when y = 0 and in that case x may not be equal to y
DS princeton - pls clarify the off. explanation
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Source: Beat The GMAT — Data Sufficiency |
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imranme318
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XY=Y^2 ===>XY=Y*Y or -Y*-Y so X=+-Y
X^2=Y^2===>+-X=+-Y ....So Both statements are required here to answer....!
X^2=Y^2===>+-X=+-Y ....So Both statements are required here to answer....!
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Ian Stewart
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This isn't right. If x*y = y*y, then we can divide by y if y is not zero. In that case x=y; otherwise y=0. There is no reason to concern yourself with the possibility that x = -y; that will *not* be true except when x=0 *and* y=0.imranme318 wrote:XY=Y^2 ===>XY=Y*Y or -Y*-Y so X=+-Y
X^2=Y^2===>+-X=+-Y ....So Both statements are required here to answer....!
