|
Author |
Message |
|
TAGS:
|
|
|
Senior Manager
Joined: 03 Aug 2012
Posts: 323
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GPA: 3.7
Followers: 2
Kudos [?]:
18
[0], given: 69
|
If (a-b)/c<0, is a>b? [#permalink]
 16 Mar 2013, 22:15
Question Stats:
75% (01:49) correct
25% (01:17) wrong based on 32 sessions
If (a-b)/c<0, is a>b? (1) c < 0 (2) a + b < 0
_________________
Plz Correct me if I am deviating somewhere!!
Consider KUDOS if the post was informative!!
Last edited by Bunuel on 17 Mar 2013, 01:37, edited 1 time in total.
Renamed the topic and edited the question.
|
|
|
|
|
|
|
Senior Manager
Joined: 03 Aug 2012
Posts: 323
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GPA: 3.7
Followers: 2
Kudos [?]:
18
[1] , given: 69
|
1
This post received
KUDOS
(a-b)/c <0 => c(a-b)/c^2 < 0 => ac -bc <0 => ac<bc Statement (1) : Tells the sign of (C) means sufficient. Statement (2) : a+b < 0 => a < -b a b a<-b Is a>b?+ + Not Poss N/A- - Yes No- + Yes No+ - Yes NoWhy the answer is not (D). Please tell what I am missing above Rgds, TGC
_________________
Plz Correct me if I am deviating somewhere!!
Consider KUDOS if the post was informative!!
|
|
|
|
|
|
Intern
Joined: 05 Mar 2013
Posts: 1
Followers: 0
Kudos [?]:
0
[0], given: 2
|
Re: If (a-b)/c<0, is a>b? [#permalink]
17 Mar 2013, 01:46
Before cross multiplying or multiplying numerator and denominator by c you should keep in mind that c should not be equal to 0
So which statement proves c won't be 0
(1) c < 0
This statement implies that c is not equal to 0
(2) a + b < 0
You aren't sure whether c would be 0 or not.
Hence, the answer should be A
Kudos please !
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 12077
Followers: 1876
Kudos [?]:
10077
[1] , given: 954
|
Re: If (a-b)/c<0, is a>b? [#permalink]
17 Mar 2013, 01:53
1
This post received
KUDOS
|
|
|
|
|
|
Senior Manager
Joined: 03 Aug 2012
Posts: 323
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GPA: 3.7
Followers: 2
Kudos [?]:
18
[0], given: 69
|
Re: If (a-b)/c<0, is a>b? [#permalink]
17 Mar 2013, 07:14
Bunuel wrote: If (a-b)/c<0, is a>b?
(1) c < 0. Multiply (a-b)/c<0 by negative c and flip the sign a-b>0 --> a>b. Sufficient.
(2) a + b < 0. The sum of two numbers is less than zero. Can we tell which of them is greater? (Can we tell whether a>b or a<b?) No, consider a=1, b=-2 and c=-1 AND a=-2, b=1 and c=1. Not sufficient.
Answer: A. What is wrong in the solution that I gave? Rgds, TGC
_________________
Plz Correct me if I am deviating somewhere!!
Consider KUDOS if the post was informative!!
|
|
|
|
|
|
GMAT Club team member
Joined: 02 Sep 2009
Posts: 12077
Followers: 1876
Kudos [?]:
10077
[0], given: 954
|
targetgmatchotu wrote: (a-b)/c <0
=> c(a-b)/c^2 < 0
=> ac -bc <0
=> ac<bc
Statement (1) : Tells the sign of (C) means sufficient.
Statement (2) : a+b < 0
=> a < -b
a b a<-b Is a>b?
+ + Not Poss N/A
- - Yes No
- + Yes No
+ - Yes No
Why the answer is not (D).
Please tell what I am missing above
Rgds,
TGC Consider one of the cases in your approach above: if both a and b are negative, it's possible that a>b as well as a<b. For example, a=-1, b=-2, and c=-1 AND a=-2, b=-1, and c=1. Hope it helps.
_________________
PLEASE READ AND FOLLOW: 11 Rules for Posting!!!
RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders
COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!
DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!, 11 New DS set. NEW!!!
What are GMAT Club Tests?
25 extra-hard Quant Tests
Find out what's new at GMAT Club - latest features and updates
|
|
|
|
|
|
Senior Manager
Joined: 03 Aug 2012
Posts: 323
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GPA: 3.7
Followers: 2
Kudos [?]:
18
[0], given: 69
|
Bunuel wrote: targetgmatchotu wrote: (a-b)/c <0
=> c(a-b)/c^2 < 0
=> ac -bc <0
=> ac<bc
Statement (1) : Tells the sign of (C) means sufficient.
Statement (2) : a+b < 0
=> a < -b
a b a<-b Is a>b?
+ + Not Poss N/A
- - Yes No
- + Yes No
+ - Yes No
Why the answer is not (D).
Please tell what I am missing above
Rgds,
TGC Consider one of the cases in your approach above: if both a and b are negative, it's possible that a>b as well as a<b. For example, a=-1, b=-2, and c=-1 AND a=-2, b=-1, and c=1. Hope it helps. Why to take c variable in picture . Given that a<-b I think appropriate would be a = -1 b = -2 (here a>b still holding a<-b) a = -2 b = -1 (here a <b still holding a<-b) Hence,wrong
_________________
Plz Correct me if I am deviating somewhere!!
Consider KUDOS if the post was informative!!
|
|
|
|
|
|
Director
Status: Final Lap Up!!!
Affiliations: NYK Line
Joined: 21 Sep 2012
Posts: 981
Location: India
GMAT 1: 410 Q35 V11
GMAT 2: 530 Q44 V20
GMAT 3: 630 Q45 V31
GPA: 3.2
WE: Engineering (Transportation)
Followers: 15
Kudos [?]:
105
[1] , given: 58
|
1
This post received
KUDOS
targetgmatchotu wrote: Bunuel wrote: targetgmatchotu wrote: (a-b)/c <0
=> c(a-b)/c^2 < 0
=> ac -bc <0
=> ac<bc
Statement (1) : Tells the sign of (C) means sufficient.
Statement (2) : a+b < 0
=> a < -b
a b a<-b Is a>b?
+ + Not Poss N/A
- - Yes No
- + Yes No
+ - Yes No
Why the answer is not (D).
Please tell what I am missing above
Rgds,
TGC Consider one of the cases in your approach above: if both a and b are negative, it's possible that a>b as well as a<b. For example, a=-1, b=-2, and c=-1 AND a=-2, b=-1, and c=1. Hope it helps. Why to take c variable in picture . Given that a<-b I think appropriate would be a = -1 b = -2 (here a>b still holding a<-b) a = -2 b = -1 (here a <b still holding a<-b) Hence,wrong Hi TGC good to see you back on the forums..........people gather courage from life's storms. I think the process you suggested is correct and has got no flaws in it....its concise...i do not find any use of third variable here. Archit
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
close
