Manhattan GMAT challenge question 11/25/02

[jigar24]

11/25/02

Question
Is xy + xy < xy ?

By subtracting xy from both sides, we can rephrase to Is xy < 0?

(1) x^2/y < 0

(2) (x^9)(y^9) < (x^8)(y^8)



The answer given is (E).. shouldn't the answer be (B)?? B clearly suggest that xy is negative .. What am I missing?

[alok.sarsidharan]

I'm not sure if the answer should be B. The answer I think is E.

From the 2nd statement, we only get xy < 1 :

Divide both sides of the inequality by (x^8)(y^8)
Thus, it looks something like :
(x^9)(y^9) / (x^8)(y^8) < (x^8)(y^8) / (x^8)(y^8)

Therefore, xy < 1 ..... which is not what is required (xy<0)

[jigar24]

thnks alok.. I often forget to check for fractions.. thanks a lot

[esledge]

Great explanation, alok. Thanks.