GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 28 May 2020, 23:33

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

If a, b, and c are positive integers, what is the greatest common divi

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 64220
If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 21 Dec 2018, 05:01
1
7
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

64% (01:22) correct 36% (01:30) wrong based on 128 sessions

HideShow timer Statistics

Most Helpful Expert Reply
Math Expert
avatar
V
Joined: 02 Aug 2009
Posts: 8602
Re: If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 24 Dec 2018, 00:56
1
1
If a, b, and c are positive integers, what is the greatest common divisor of a, b and c?

GCD means the largest number which has all three numbers a, b and c in its table.

(1) The greatest common divisor of a and b is 3
this means GCD of a, b and c can be only 3, but we don't know if 3 is a factor of c or not.
If yes, GCD is 3, otherwise it is 1.

Insufficient

(2) The greatest common divisor of b and c is 4
this means GCD of a, b and c can be only 4, but we don't know if 4 is a factor of a or not.
If yes, GCD is 4, otherwise it is 1.

Insufficient

Combined..
It can be only 1

C
_________________
General Discussion
Intern
Intern
User avatar
B
Joined: 19 Nov 2017
Posts: 14
Location: Singapore
Concentration: Technology, Entrepreneurship
GMAT 1: 590 Q45 V27
GMAT 2: 700 Q48 V37
GPA: 3.44
WE: Engineering (Computer Software)
Reviews Badge
Re: If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 23 Dec 2018, 03:19
I got E.

Since by St#2 : b = 4x , c = 4y , not enough

And by St#1 : a = 3z , b = 3x , not enough

Combining ,in (c)
a= 3z
b = 3*4*x
c = 4*y

We cannot get common factor from here, hence (e)
Manager
Manager
avatar
G
Joined: 02 Aug 2015
Posts: 151
If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 23 Dec 2018, 07:11
1
aru010 wrote:
I got E.

Since by St#2 : b = 4x , c = 4y , not enough

And by St#1 : a = 3z , b = 3x , not enough

Combining ,in (c)
a= 3z
b = 3*4*x
c = 4*y

We cannot get common factor from here, hence (e)


aru010

What about the number 1?

Cheers!
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 64220
Re: If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 24 Dec 2018, 00:16
CEO
CEO
User avatar
V
Joined: 03 Jun 2019
Posts: 2899
Location: India
GMAT 1: 690 Q50 V34
WE: Engineering (Transportation)
Premium Member Reviews Badge CAT Tests
Re: If a, b, and c are positive integers, what is the greatest common divi  [#permalink]

Show Tags

New post 08 Oct 2019, 03:50
1
Bunuel wrote:
If a, b, and c are positive integers, what is the greatest common divisor of a, b and c?


(1) The greatest common divisor of a and b is 3
(2) The greatest common divisor of b and c is 4


Asked: If a, b, and c are positive integers, what is the greatest common divisor of a, b and c?


(1) The greatest common divisor of a and b is 3
Since c is unknown
NOT SUFFICIENT

(2) The greatest common divisor of b and c is 4
Since a is unknown
NOT SUFFICIENT

(1) + (2)
(1) The greatest common divisor of a and b is 3
(2) The greatest common divisor of b and c is 4
The greatest common divisor of a, b & c is 1.
SUFFICIENT

IMO C
_________________
Kinshook Chaturvedi
Email: kinshook.chaturvedi@gmail.com
GMAT Club Bot
Re: If a, b, and c are positive integers, what is the greatest common divi   [#permalink] 08 Oct 2019, 03:50

If a, b, and c are positive integers, what is the greatest common divi

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





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