It is currently 23 Jan 2018, 12:08

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

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

Expert Post
1 KUDOS received
Math Expert
User avatar
D
Joined: 02 Aug 2009
Posts: 5545
If c > d > b, is d an integer? [#permalink]

Show Tags

New post 08 Dec 2017, 00:38
1
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

56% (00:49) correct 44% (01:08) wrong based on 52 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
[Reveal] Spoiler: OA

_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html


BANGALORE/-

Senior Manager
Senior Manager
User avatar
S
Joined: 05 Dec 2016
Posts: 260
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
G
Joined: 21 Aug 2013
Posts: 681
Location: India
Premium Member CAT Tests
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: 18
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
Re: If c > d > b, is d an integer?   [#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  


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®.