What is the greatest common factor of positive integers x : DS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 22:24

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# What is the greatest common factor of positive integers x

 post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Manager
Joined: 12 Feb 2006
Posts: 115
Followers: 1

Kudos [?]: 68 [0], given: 0

What is the greatest common factor of positive integers x [#permalink]

### Show Tags

10 Feb 2007, 21:17
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

What is the greatest common factor of positive integers x and y?

1. The greatest common factor of x/2 and y/2 is 5.

2. X and Y are even.

Thanks,
Director
Joined: 12 Jun 2006
Posts: 532
Followers: 2

Kudos [?]: 117 [0], given: 1

### Show Tags

11 Feb 2007, 01:49
E?

Don't X and Y say the same thing, they are even #s.
Director
Joined: 05 Feb 2006
Posts: 898
Followers: 3

Kudos [?]: 107 [0], given: 0

### Show Tags

13 Feb 2007, 04:25
I choose A.

if x/2 and y/2 have a gcf of 5 it means that x and y have only two factors (= 5 and 2)... in common. Thus gcf of x and y=10

Some examples:

(2*5*5*5)/2 and (2*5)/2 : gcf=5; x and y gcf=10
(2*2*5*5)/2 and (2*5)/2 : gcf=5; x and y gcf=10
(2*3*3*5)/2 and (2*5)/2 : gcf=5; x and y gcf=10
(2*5*5*7)/2 and (2*3*5)/2 : gcf=5; x and y gcf=10
Senior Manager
Joined: 04 Jan 2006
Posts: 279
Followers: 1

Kudos [?]: 37 [0], given: 0

### Show Tags

13 Feb 2007, 07:44
I'm not good with LCM and GCM. However, I will try to solve this one.

What is the GCM(x,y)?

(1) GCM(x/2, y/2) = 5
Assuming m not= n. Both m and n do not share any common factor.
x/2 = m x 5
y/2 = n x5

If we set the equation above, we can be certain that the GCM(x/2, y/2) = 5

x = 2 x 5 x m
y = 2 x 5 x n

Since m not= n
GCM(x,y) = 2 x 5 = 10 SUFF

(2) will come back to this one later :p

13 Feb 2007, 07:44
Display posts from previous: Sort by

# What is the greatest common factor of positive integers x

 post reply Question banks Downloads My Bookmarks Reviews Important topics

 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®.