If x + y = 10, is x = 4? (1) y is not 6. (2) y is 4.

Question

If x + y = 10, is x = 4?

(1) y is not 6.
(2) y is 4.

Kudos for a correct  solution .

GMATinsight · Answer

Statement 1 : y is not 6 
i.e. x is not 4. Hence,
 Sufficient

Statement 2 : y = 4 
i.e. x = 6
i.e. x is not 4
 Sufficient

Answer: option D

VenoMfTw · Answer

IMO : D

Question Stem: If x + y = 10, is x = 4?

Another way of putting the question will be 
x is 4 when y = 6.
  Thus is y=6?    Now check with the statements

St 1 : y is not 6 
Gives us NO. Thus x is not equal to 4
 Hence suff

St 2: y is 4 
Gives us NO. Thus x is not equal to 4
 Hence suff

AA2014 · Answer

Each statement definitely tells us that x cannot be equal to 4.
Hence each statement is SUFFICIENT.

Ans. = D

AmoyV · Answer

The question nowhere mentions that y is positive. So y could also be -14 and hence x=4 to satisfy the equation.

I believe the answer should be B. Can anyone tell me where I am going wrong?

rachelclarky · Answer

That was my thinking as well, I think you're correct, only option B is sufficient.

longfellow · Answer

answer is D as both statements prove that x is not equal to 4

rudra316 · Answer

If y = -14, value of x will be 24

Shrikunj · Answer

Since both x and y could be either positive or negative integers,or even fractions, I think only the second statement is sufficient. Hence the answer should be B.

EMPOWERgmatRichC · Answer

Hi Shrikunj,

In DS questions, any time you 'think' you know the correct answer, then you should be able to prove it. If you think that Fact 1 is insufficient, then where is your PROOF?

We're told that X+Y= 10. We're asked if X = 4. This is a YES/NO question.

Fact 1: Y is NOT 6.

So what COULD Y be....? And what would that make X....? And what would the answer to the question be....?

GMAT assassins aren't born, they're made,
Rich

OptimusPrepJanielle · Answer

If x + y = 10, is x = 4?

(1) y is not 6.  sufficient (no) x would have to equal 4 if y were 6 (to add up to 10), but y is not 6 so x can be anything 
(2) y is 4.  sufficient (no) x cannot be 4 if y is, since the sum would be 8 and not 10.

D

D3N0 · Answer

Ans: D
given to us x+y=10, is x=4? well x can be four only if y=6. only these values will satisfy the equation given.
1) y is not 6 means x can not be 4.  
2) y is 4 means x is 6

Ans: D both statement alone are sufficient to ans the question.

Shrikunj · Answer

Thanks, figured out where i went wrong!

D3N0 · Answer

Well think about it this way...
If Y =-14 and X=4 then X+Y= -10 
is it the same equation which is given in the question stem. no 
so ofcourse y can not be -14 to satisfy the equation.

so both option gives us the ans of the question sufficiently in yes and no format.

Bunuel · Answer

If x + y = 10, is x = 4?

Notice that since it's given that x + y = 10, then the question " is x = 4 " is equivalent is he questions is " is y = 6 ".

(1) y is not 6. Directly gives a NO answer to the question. Sufficient.
(2) y is 4. Directly gives a NO answer to the question. Sufficient.

Answer: D.

Hope it's clear.

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.

If x + y = 10, is x = 4? (1) y is not 6. (2) y is 4.

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

If x + y = 10, is x = 4? (1) y is not 6. (2) y is 4.

Prep Toolkit

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