Last visit was: 08 Sep 2024, 14:47 It is currently 08 Sep 2024, 14:47
Toolkit
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.
Request Expert Reply

# The greatest common factor of two numbers is 5!. Which of the followin

SORT BY:
Tags:
Show Tags
Hide Tags
Math Expert
Joined: 02 Sep 2009
Posts: 95354
Own Kudos [?]: 656780 [37]
Given Kudos: 87193
Most Helpful Reply
Math Expert
Joined: 02 Sep 2009
Posts: 95354
Own Kudos [?]: 656780 [6]
Given Kudos: 87193
General Discussion
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11514
Own Kudos [?]: 35869 [0]
Given Kudos: 333
Manager
Joined: 07 Dec 2009
Posts: 69
Own Kudos [?]: 103 [1]
Given Kudos: 375
GMAT Date: 12-03-2014
Re: The greatest common factor of two numbers is 5!. Which of the followin [#permalink]
1
Kudos
GCF is the product of common factors of the numbers involved.

GCF = 5!

a = 8! = 8*7*6*5!

b will certainly have 5! and cannot have any more common factors with a (as this will increase the GCF)

Looking at the answers only 5 (5!) and 8! will have GCF as 5!

Ans C
Intern
Joined: 15 Aug 2013
Posts: 44
Own Kudos [?]: 118 [4]
Given Kudos: 7
Re: The greatest common factor of two numbers is 5!. Which of the followin [#permalink]
4
Kudos
It is given that GCD of two numbers is 5! => this is the maximum common factor in those two numbers.

First number is 8! = 8*7*6*5!
Lets review all the options for second number -

A. 3(5!) - here 3 is also common in addition to 5!. Hence 5! cant be the GCD of these two numbers
B. 4(5!) - Here 4 is common besides 5! and so this option is rejected
C. 5(5!) - only 5! is common in the two numbers and hence the Answer.
D. 6(5!) - 6 is common besides 5! and hence rejected on similar grounds
E. 7(5!) - 7 is common besides 5! and so this is aso rejected

Hence ans is C.
Non-Human User
Joined: 09 Sep 2013
Posts: 34784
Own Kudos [?]: 876 [0]
Given Kudos: 0
Re: The greatest common factor of two numbers is 5!. Which of the followin [#permalink]
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Re: The greatest common factor of two numbers is 5!. Which of the followin [#permalink]
Moderator:
Math Expert
95354 posts