Find all School-related info fast with the new School-Specific MBA Forum

It is currently 20 Oct 2014, 04:07

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

What is the greatest common divisor of positive integers m

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 17 Dec 2005
Posts: 162
Followers: 1

Kudos [?]: 7 [0], given: 0

What is the greatest common divisor of positive integers m [#permalink] New post 16 Jun 2006, 21:39
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
What is the greatest common divisor of positive integers m and n?

C1. m is a prime number

C2. 2n = 7m
Director
Director
User avatar
Joined: 06 May 2006
Posts: 782
Followers: 3

Kudos [?]: 14 [0], given: 0

 [#permalink] New post 16 Jun 2006, 22:02
Can't say. Should be E.

What if n is a multiple of m? Not addressed in either of the choices.
Manager
Manager
avatar
Joined: 07 Jul 2005
Posts: 65
Followers: 1

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

 [#permalink] New post 16 Jun 2006, 22:18
I will go with D.

Both statements individually are sufficient.
Manager
Manager
avatar
Joined: 10 May 2006
Posts: 186
Location: USA
Followers: 1

Kudos [?]: 3 [0], given: 0

Re: DS: Number Properties (GMATPrep problem) [#permalink] New post 17 Jun 2006, 03:24
mrmikec wrote:
What is the greatest common divisor of positive integers m and n?

C1. m is a prime number

C2. 2n = 7m


I'll go with C.

1 - Insufficient. we don't know anything about n.

m=3
n=3 Greatest divisor is 3

m=7
n=2 Greatest divisor is 1

2 - insufficient, multiple values for this equation


Together - 2n = 7m.....given that 2n is even, 7m must also be even. However, we know that m is prime..therefore m must be 2 in order for 7m to be even.

m must be 2, and n must be 7.

C.
Manager
Manager
User avatar
Joined: 17 Dec 2005
Posts: 162
Followers: 1

Kudos [?]: 7 [0], given: 0

Re: DS: Number Properties (GMATPrep problem) [#permalink] New post 17 Jun 2006, 12:00
tl372 wrote:
mrmikec wrote:
What is the greatest common divisor of positive integers m and n?

C1. m is a prime number

C2. 2n = 7m


I'll go with C.

1 - Insufficient. we don't know anything about n.

m=3
n=3 Greatest divisor is 3

m=7
n=2 Greatest divisor is 1

2 - insufficient, multiple values for this equation


Together - 2n = 7m.....given that 2n is even, 7m must also be even. However, we know that m is prime..therefore m must be 2 in order for 7m to be even.

m must be 2, and n must be 7.

C.


I got B but now I see where i went wrong. Great explanation tl372! 8-)

originally i though

if 2n=7m, then

2n = some multiple of 7, 2, and any integer
conversely,
7m = some multiple of 2, 7, and any integer

so can you conclude that 7 is the greatest common divisor?

or do you mean that the "any integer" can be equal and thus the greatest common divisor...

but

so if 2n = 140 then, 2, 7, 10
7m = 140, 7, 2, 10

GCD is 10. you could have an infinite number of GCD depending on the value of the integer selected.

But if m is prime and 7m is even, m=2. and the GCD is 7.
Re: DS: Number Properties (GMATPrep problem)   [#permalink] 17 Jun 2006, 12:00
    Similar topics Author Replies Last post
Similar
Topics:
What is the greatest common divisor of positive integers m marcodonzelli 3 12 Mar 2008, 12:05
what is the greatest common divisor of positive integers m young_gun 4 06 Nov 2007, 12:49
What is the greatest common divisor of positive integers m dancer 9 25 Oct 2006, 18:29
What is the greatest common divisor of positive integers m gmat_crack 5 08 Apr 2006, 20:36
What is the greatest common divisor of positive integers m twixt 4 22 Nov 2004, 06:50
Display posts from previous: Sort by

What is the greatest common divisor of positive integers m

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.