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.
It appears that you are browsing the GMAT Club forum unregistered!
Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club
Registration gives you:
Tests
Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.
Applicant Stats
View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more
Books/Downloads
Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!
Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:
Re: If the least common multiple of a positive integer [#permalink]
13 Jun 2008, 05:37
1
This post received KUDOS
Expert's post
1
This post was BOOKMARKED
D
fist way:
LCM=120=3*2^3*5
1. LCM contains prime number 5, so m or n or both also contain 5. 2. if m:n=3:4 then only both m and m contain 5. Therefore, GCD is 5 or 10. 3. LCM contains 2^3, but in ratio m:n we have only 4=2^2. So, both m and m contain 2. GCD=10.
second way:
m*n=LCM*GCD - it is a formula. m*n=3x*4x=120*GCD ---> GCD=x^2/10 ---> only 10 works. _________________
Re: If the least common multiple of a positive integer [#permalink]
13 Jun 2008, 05:45
walker wrote:
D
fist way:
LCM=120=3*2^3*5
1. LCM contains prime number 5, so m or n or both also contain 5. 2. if m:n=3:4 then only both m and m contain 5. Therefore, GCD is 5 or 10. 3. LCM contains 2^3, but in ratio m:n we have only 4=2^2. So, both m and m contain 2. GCD=10.
I like this. Thanks !
walker wrote:
second way:
m*n=LCM*GCD - it is a formula. m*n=3x*4x=120*GCD ---> GCD=x^2/10 ---> only 10 works.
Thanks for the refresh on the formula, I did not remember.
Re: If the least common multiple of a positive integer m and n [#permalink]
20 Oct 2013, 15:04
1
This post received KUDOS
1
This post was BOOKMARKED
vd wrote:
If the least common multiple of a positive integer m and n is 120 and m:n is 3:4 what is the greatest common factor of m and n
3 5 6 10 12
Please provide detailed explanations on how to solve this
many thanks
I just plugged in numbers for m & n. If the ratio is 3:4, then using 3 & 4 for their values works fine, since we're trying to find the GCF, and not the actual values of m&n,
Re: If the least common multiple of positive integer m and n is [#permalink]
12 Jan 2015, 00:46
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: If the least common multiple of positive integer m and n is [#permalink]
12 Jan 2015, 15:29
2
This post received KUDOS
Expert's post
Hi All,
There are a number of different ways to approach this question. Given the "restrictions" that are in the prompt, if you're not sure what to do with a question such as this, you can always "brute force" it....
'Brute Force' is essentially just throwing numbers at a situation until you find the correct answer (or at least find the pattern that will lead you to the correct answer). It's not particularly elegant, but in the right circumstances it can be a really fast way to get to the correct answer.
In this question, we're told: 1) M and N are positive integers 2) The LCM of M and N is 120 3) The ratio of M:N is 3:4
I'm going to focus on how the second and third "restrictions" interact....
If M=3 and N=4, then the LCM would be 12 (not 120). Notice the "times 10" difference?....
What if... M = 30 and N = 40. Multiples of 30: 30, 60, 90, 120 Multiples of 40: 40, 80, 120 The LCM IS 120.
With 30 and 40 as our two values, it's not hard to find the GREATEST common factor. It has to be 10.
As I’m halfway through my second year now, graduation is now rapidly approaching. I’ve neglected this blog in the last year, mainly because I felt I didn’...
Hilary Term has only started and we can feel the heat already. The two weeks have been packed with activities and submissions, giving a peek into what will follow...
Ninety-five percent of the Full-Time Class of 2015 received an offer by three months post-graduation, as reported today by Kellogg’s Career Management Center(CMC). Kellogg also saw an increase...