Is x 0 ? (1) xy 0 (2) x + y 0

Question

Is x > 0 ?

(1) xy > 0
(2) x + y > 0

IanStewart · Accepted Answer

From Statement 1, x and y have the same sign. Not sufficient, since both could be negative.

From Statement 2, x and y could certainly both be positive, but it might be that x = -1 and y = 2, say. Not sufficient.

Taken together, we know from statement 1 that x and y share the same sign. Could they both be negative? No, because if they were, x+y would need to be negative, and that's not the case, as we learn from statement 2. So both x and y need to be positive, and the answer is C.

ezhilkumarank · Answer

Statement A:

xy > 0

(x, y) could be (-ve, -ve) or (+ve, +ve). Since there are two scenarios, we can't say whether x is +ve.

Insufficient.

Statement B:

x + y > 0

(x,y) can be (3, 4) or (7, -6) or (-8, 25). Hence cannot say x is +ve.

Insufficient.

Combining Statement A & B, xy > 0 & x+y > 0.
(x, y) could be (+ve, +ve) and not (-ve, -ve).
(x,y) can be (3, 4) and not (7, -6) or (-8, 25).

Hence statement A and B can be used together and not alone to answer this question.

Answer : C.

NoHalfMeasures · Answer

is there an algebraic solution to this problem? thanks

Mamsi · Answer

Anyone could give more explaination? Why not E?

LevanKhukhunashvili · Answer

1 stm just tels us that x and y have the same +- nature and none of them is 0
2 stm tells us that x>-y

From the both statements we have got
If x is positive y is positive and satisfy the second statement x>-y
If x is negative then y is negative too, with this we cant satisfy the second statement negative number cant be more than any positive number

So only option one (when x and y are positive) is left

Hope it's clear

Mamsi · Answer

It's good for me now! Thank

bumpbot · Answer

Automated notice from GMAT Club BumpBot: 

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

 This post was generated automatically.

Is x > 0 ? (1) xy > 0 (2) x + y > 0

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions