Author 
Message 
Director
Joined: 29 Aug 2005
Posts: 836

If x+y+z>0, is z>1? 1) z>x+y+1 2)x+y+1<0 [#permalink]
Show Tags
08 Dec 2008, 14:27
Question Stats:
0% (00:00) correct 0% (00:00) wrong based on 1 sessions
HideShow timer Statistics
If x+y+z>0, is z>1? 1) z>x+y+1 2)x+y+1<0 == Message from GMAT Club Team == This is not a quality discussion. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.



Intern
Joined: 05 Oct 2008
Posts: 14

Re: DS: OG suppl. 85 [#permalink]
Show Tags
08 Dec 2008, 15:49
From 2) we get z+1 < 0 I.e. z>1 ==> 2) sufficient
1) is not sufficient: for example, consider (x,y,z)=(0.5,0.2,1): x+y+z>0 and z>x+y+1 and for (x,y,z)=(0.5,0.2,3): also both inequalities are verified
answer is B



Manager
Joined: 14 Oct 2008
Posts: 160

Re: DS: OG suppl. 85 [#permalink]
Show Tags
08 Dec 2008, 16:05
I would go for E.
I didn't understand how statement 2 is sufficient as stated by echizen
according to statement 2 , x+y+1 < 0 , so x+y < 1 , so say x+y = 2
from qs, x+y+z>0 , 2+z>0 , z>2 , but that does not necessarily mean z>1 ?? Hence statement 2 is also insufficient.
Whats the QA ? ( pls post it along with explanation if given )



Senior Manager
Joined: 21 Apr 2008
Posts: 265
Location: Motortown

Re: DS: OG suppl. 85 [#permalink]
Show Tags
08 Dec 2008, 16:16
botirvoy wrote: If x+y+z>0, is z>1? 1) z>x+y+1 2)x+y+1<0 B x+y+z>0 x+y+1+z>1 stmt1 : from z>x+y+1 and x+y+z+1>1 > z could be 2/3 or >1  Not Suff stmt2: since x+y+1<0, z >1  Suff



Manager
Joined: 30 Sep 2008
Posts: 111

Re: DS: OG suppl. 85 [#permalink]
Show Tags
08 Dec 2008, 16:17
gameCode wrote: I would go for E.
I didn't understand how statement 2 is sufficient as stated by echizen
according to statement 2 , x+y+1 < 0 , so x+y < 1 , so say x+y = 2
from qs, x+y+z>0 , 2+z>0 , z>2 , but that does not necessarily mean z>1 ?? Hence statement 2 is also insufficient.
Whats the QA ? ( pls post it along with explanation if given ) Q: x+y+z>0 => x + y >  z (2): x+y+1<0 => x + y < 1 => z < 1 => z > 1 => suff



Manager
Joined: 23 Nov 2008
Posts: 79

Re: DS: OG suppl. 85 [#permalink]
Show Tags
09 Dec 2008, 17:41
gameCode wrote: I would go for E.
I didn't understand how statement 2 is sufficient as stated by echizen
according to statement 2 , x+y+1 < 0 , so x+y < 1 , so say x+y = 2
from qs, x+y+z>0 , 2+z>0 , z>2 , but that does not necessarily mean z>1 ?? Hence statement 2 is also insufficient.
Whats the QA ? ( pls post it along with explanation if given ) The two inequalities say x+y<1, and x+y+z>0, therefore, z will need to be greater than 1 (and in your example, greater than 2), otherwise x+y(which is <1)+z will be less than 0.



SVP
Joined: 07 Nov 2007
Posts: 1760
Location: New York

Re: DS: OG suppl. 85 [#permalink]
Show Tags
09 Dec 2008, 21:48
botirvoy wrote: If x+y+z>0, is z>1? 1) z>x+y+1 2)x+y+1<0 1) z>x+y+1 > z+z >(x+y+z) +1 > 2z>1 > z>1/2 Not sufficient 2) )x+y+1<0 > x+y+z+1<z > z>1 Sufficient B
_________________
Your attitude determines your altitude Smiling wins more friends than frowning



VP
Joined: 18 May 2008
Posts: 1203

Re: DS: OG suppl. 85 [#permalink]
Show Tags
09 Dec 2008, 22:01
gameCode wrote: I would go for E.
I didn't understand how statement 2 is sufficient as stated by echizen
according to statement 2 , x+y+1 < 0 , so x+y < 1 , so say x+y = 2
from qs, x+y+z>0 , 2+z>0 , z>2 , but that does not necessarily mean z>1 ?? Hence statement 2 is also insufficient.
Whats the QA ? ( pls post it along with explanation if given ) If Z>2 then it is definitely greater than 1.



Manager
Joined: 14 Oct 2008
Posts: 160

Re: DS: OG suppl. 85 [#permalink]
Show Tags
09 Dec 2008, 22:26
yeah i realize my mistake in that one. I get confused in this kind of DS. Thanks everyone.



Director
Joined: 29 Aug 2005
Posts: 836

Re: DS: OG suppl. 85 [#permalink]
Show Tags
22 Dec 2008, 06:15
OA is indeed B. Thanks everyone!



VP
Joined: 05 Jul 2008
Posts: 1369

Re: DS: OG suppl. 85 [#permalink]
Show Tags
28 Dec 2008, 13:46
x2suresh wrote: botirvoy wrote: If x+y+z>0, is z>1? 1) z>x+y+1 2)x+y+1x+y+1 > z+z >(x+y+z) +1 > 2z>1 > z>1/2 Not sufficient
2) )x+y+1 x+y+z+1 z>1 Sufficient
B Nice way of doing it by adding Z on both sides. Got a B == Message from GMAT Club Team == This is not a quality discussion. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.




Re: DS: OG suppl. 85
[#permalink]
28 Dec 2008, 13:46






