GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 15 Nov 2018, 06:52

ISB R1 results on Nov 15:

Join Chat Room for Live Updates


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 in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
  • Free GMAT Strategy Webinar

     November 17, 2018

     November 17, 2018

     07:00 AM PST

     09:00 AM PST

    Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
  • GMATbuster's Weekly GMAT Quant Quiz # 9

     November 17, 2018

     November 17, 2018

     09:00 AM PST

     11:00 AM PST

    Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.

If c > d > b, is d an integer?

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7034
If c > d > b, is d an integer?  [#permalink]

Show Tags

New post 08 Dec 2017, 00:38
1
2
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

50% (01:31) correct 50% (01:39) wrong based on 60 sessions

HideShow timer Statistics

If c > d > b, is d an integer?

(1) c = b + 1
(2) \(d=\frac{c+b}{2}\)

New tricky question

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html
3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html


GMAT online Tutor

Manager
Manager
User avatar
S
Joined: 05 Dec 2016
Posts: 244
Concentration: Strategy, Finance
GMAT 1: 620 Q46 V29
GMAT ToolKit User
Re: If c > d > b, is d an integer?  [#permalink]

Show Tags

New post 08 Dec 2017, 01:04
(1) c=1,5 b=0,5 then d lie in 0,5<d<1,5 and can be 1 or 0,7 so it is unclear whether it is integer or not.
Insufficient
(2) d=(c+b)/2
c= 1,5 b=0,5 d= (1,5+0,5)/2=1 - integer
c=1,8 b=0,8 d= (1,8+0,8)/2=1,3 - NOT an integer
(1) + (2)
c= 1,5 b=0,5 d= (1,5+0,5)/2=1 - integer
c=1,8 b=0,8 d= (1,8+0,8)/2=1,3 - NOT an integer


Answer should be E I guess
DS Forum Moderator
avatar
P
Joined: 21 Aug 2013
Posts: 1365
Location: India
Premium Member
Re: If c > d > b, is d an integer?  [#permalink]

Show Tags

New post 08 Dec 2017, 09:47
chetan2u wrote:
If c > d > b, is d an integer?

(1) c = b + 1
(2) \(d=\frac{c+b}{2}\)

New tricky question


(1) If b is an integer, then c=b+1 is also an integer, else not. But in any case d might or might not be an integer. So Insufficient.

(2) d = (c+b)/2 This tells us that d is the arithmetic mean of c & b, and thus c, d, b are in Arithmetic Progression (AP). But we cant say whether any or all of them are integers or not. Eg, c, d, b could be 3, 2, 1 respectively or they could be 3.3, 3.2, 3.1 respectively. So Insufficient.

Combining the two statements, c, d, b are in AP and c=b+1. But we could have a case where d is an integer (eg, c/d/b could be 3/2.5/2 respectively) OR we could also have a case where d is NOT an integer (eg, c/d/b could be 3.5/3/2.5 respectively). So d might or might not be an integer still. Insufficient.

Hence E answer
Intern
Intern
avatar
B
Joined: 02 Jun 2016
Posts: 35
Location: India
GMAT 1: 660 Q44 V36
GMAT 2: 680 Q46 V38
GPA: 3.77
WE: General Management (Computer Software)
Re: If c > d > b, is d an integer?  [#permalink]

Show Tags

New post 10 Dec 2017, 04:19
Another approach-
S1: c= b+1
If c and b were integers, then this statement tells c and b are consecutive integers, so d, which lies between them has to be non-integer. Then our answer to the question would be a NO. But since it is not given that c and b are integers, we have to consider the case if c and b are both non-integers with a difference of 1 (e.g.. 1.5 and 0.5), then it is possible that d is an integer and answer to question would be YES.
Thus Statement 1 is INSUFFICIENT.

S2: d = (b+c)/2

If sum of b and c is even, then d will be integer, so answer to question will be YES.
If sum of b and c is odd, then d is not an integer. So answer to question is NO.
Thus, statement 2 is INSUFFICIENT.

Combine (1) and (2), it says:
d = (2b+1)/2

One may falter here thinking, 2b+1 has to be ODD, so d is definitely not integer. However, one should not forget that b can be non-integer e.g. 1.5, and then d will be an integer. So both statements combined are INSUFFICIENT.

Answer: E

Posted from my mobile device
GMAT Club Bot
Re: If c > d > b, is d an integer? &nbs [#permalink] 10 Dec 2017, 04:19
Display posts from previous: Sort by

If c > d > b, is d an integer?

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.