It is currently 14 Dec 2017, 15:01

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is a < b? (1) |a – b| = b – a (2) a/b < 1

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Intern
Intern
avatar
B
Joined: 31 May 2017
Posts: 8

Kudos [?]: 13 [0], given: 4

Location: United States
Concentration: Economics, Social Entrepreneurship
GPA: 3.74
Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 04 Jun 2017, 13:20
3
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

32% (01:12) correct 68% (01:12) wrong based on 114 sessions

HideShow timer Statistics

Is a < b?

(1) |a – b| = b – a
(2) a/b < 1
[Reveal] Spoiler: OA

Kudos [?]: 13 [0], given: 4

2 KUDOS received
Intern
Intern
avatar
B
Joined: 31 May 2017
Posts: 8

Kudos [?]: 13 [2], given: 4

Location: United States
Concentration: Economics, Social Entrepreneurship
GPA: 3.74
Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 04 Jun 2017, 13:27
2
This post received
KUDOS

Detailed Answer



Is a < b?
I. |a – b| = b – a
II. a/b < 1

I. |a-b| = b-a means b-a ≥ 0, or b ≥ a.
So a<b or a=b are both satisfactory answers => Insufficient

II. a/b<1, implying that b different than 0. We have two cases: if b > 0 then a < b, and if b < 0, then a > b => Insufficient

Both Statement together are sufficient to get to the conclusion a < b, answer C

Kudos [?]: 13 [2], given: 4

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42607

Kudos [?]: 135660 [0], given: 12705

Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 04 Jun 2017, 22:16
mahdwen wrote:

Detailed Answer



Is a < b?
I. |a – b| = b – a
II. a/b < 1

I. |a-b| = b-a means b-a ≥ 0, or b ≥ a.
So a<b or a=b are both satisfactory answers => Insufficient

II. a/b<1, implying that b different than 0. We have two cases: if b > 0 then a < b, and if b < 0, then a > b => Insufficient

Both Statement together are sufficient to get to the conclusion a < b, answer C


Thst's correct.

Check more questions to practice:

DS Abolute Values Questions to practice: http://gmatclub.com/forum/search.php?se ... &tag_id=37
PS Abolute Values Questions to practice: http://gmatclub.com/forum/search.php?se ... &tag_id=58

Hard set on Abolute Values: http://gmatclub.com/forum/inequality-an ... 86939.html
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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. ,11 Mixed Questions, 12 Fresh Meat

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., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135660 [0], given: 12705

Manager
Manager
avatar
B
Joined: 06 Nov 2016
Posts: 96

Kudos [?]: 19 [0], given: 15

Location: India
GMAT 1: 710 Q49 V37
GPA: 2.8
Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 03:24
Can someone please explain why the answer is not Option A.

I know why statement 2 is insufficient as the case changes for positive and negative numbers.

Kudos [?]: 19 [0], given: 15

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 42607

Kudos [?]: 135660 [1], given: 12705

Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 06:03
1
This post received
KUDOS
Expert's post
sonikavadhera wrote:
Can someone please explain why the answer is not Option A.

I know why statement 2 is insufficient as the case changes for positive and negative numbers.


(1) |a – b| = b – a. So, |a – b| = -(a - b), which means that \(a \leq b\). So, a could be equal to b (answer NO) as well as a could be less than b (answer YES). Not sufficient.

Hope it's clear.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

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. ,11 Mixed Questions, 12 Fresh Meat

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., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Kudos [?]: 135660 [1], given: 12705

Manager
Manager
avatar
B
Joined: 06 Nov 2016
Posts: 96

Kudos [?]: 19 [0], given: 15

Location: India
GMAT 1: 710 Q49 V37
GPA: 2.8
Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 10:37
Bunuel wrote:
sonikavadhera wrote:
Can someone please explain why the answer is not Option A.

I know why statement 2 is insufficient as the case changes for positive and negative numbers.


(1) |a – b| = b – a. So, |a – b| = -(a - b), which means that \(a \leq b\). So, a could be equal to b (answer NO) as well as a could be less than b (answer YES). Not sufficient.

Hope it's clear.


Oh I forgot the equal possibility. Thanks.

Kudos [?]: 19 [0], given: 15

Intern
Intern
avatar
B
Joined: 23 Feb 2017
Posts: 38

Kudos [?]: 1 [0], given: 8

Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 18:51
Hi,
Why B is not sufficient.. given a/b<1 => a<b.. which is what we are trying to prove right.. or am I missing something more fundamental in inequalities?

Kudos [?]: 1 [0], given: 8

1 KUDOS received
Manager
Manager
avatar
S
Status: GMAT...one last time for good!!
Joined: 10 Jul 2012
Posts: 71

Kudos [?]: 6 [1], given: 18

Location: India
Concentration: General Management
GMAT 1: 660 Q47 V34
GPA: 3.5
GMAT ToolKit User Reviews Badge
Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 21:53
1
This post received
KUDOS
sasidharrs wrote:
Hi,
Why B is not sufficient.. given a/b<1 => a<b.. which is what we are trying to prove right.. or am I missing something more fundamental in inequalities?


We cannot multiply b on both sides as we do not know the sign on 'b'.
Never multiply/divide on both sides unless you are sure of the sign. When positive its the way you put it, if negative the inequality sign changes.
_________________

Kudos for a correct solution :)

Kudos [?]: 6 [1], given: 18

DS Forum Moderator
avatar
S
Joined: 21 Aug 2013
Posts: 568

Kudos [?]: 185 [0], given: 289

Location: India
Premium Member CAT Tests
Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 05 Jun 2017, 22:09
sasidharrs wrote:
Hi,
Why B is not sufficient.. given a/b<1 => a<b.. which is what we are trying to prove right.. or am I missing something more fundamental in inequalities?


Hi

In case of inequalities, you cannot multiply or divide both sides by a variable until and unless you know the sign of that variable (positive or negative)

So if you are given: a/b < 1 you will have to take both the cases:

Case 1. b is positive. In this case, we will multiply both sides by b, and since b is positive, the sign of inequality will Not change. So
a/b * b < 1*b or a < b

Case 2. b is negative. In this case, we will multiply both sides by b, and since b is negative, the sign of inequality Will change. So
a/b * b > 1*b or a > b

Hope this helps

Kudos [?]: 185 [0], given: 289

Intern
Intern
avatar
B
Joined: 12 Oct 2017
Posts: 37

Kudos [?]: 21 [0], given: 13

Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1 [#permalink]

Show Tags

New post 01 Nov 2017, 01:19
(1) |a – b| = b – a => |a – b| = -a + b = - (a-b) => a-b ≤ 0 => insufficient
(2) a/b = 1 => (a-b)/ b < 0. We have 2 cases: b<0 and a<b or b>0 and a>b => insufficient

(1) + (2) => a-b <0 => a <b => sufficient. Hence, the answer is C
----

Kindly press +1 kudos if the explanation is clear!
Thank you :-)

Kudos [?]: 21 [0], given: 13

Re: Is a < b? (1) |a – b| = b – a (2) a/b < 1   [#permalink] 01 Nov 2017, 01:19
Display posts from previous: Sort by

Is a < b? (1) |a – b| = b – a (2) a/b < 1

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.