NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 02:52 It is currently 24 Apr 2024, 02:52
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

If the least common multiple of integers x and y is 840,

SORT BY:
Date
Kudos
   1   2 
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
B
acegmat123
Manager
Manager
Joined: 28 Jun 2016
Posts: 153
Own Kudos [?]: 190 [0]
Given Kudos: 99
Location: Canada
Concentration: Operations, Entrepreneurship
Send PM
Re: If the least common multiple of integers x and y is 840, [#permalink] New post   03 Oct 2016, 11:03
If there are three numbers x,y,z

Can we say that,

x*y*z=LCM*GCD^2 ??


Sent from my iPhone using GMAT Club Forum mobile app
User avatar
L
KarishmaB
Tutor
Joined: 16 Oct 2010
Posts: 14815
Own Kudos [?]: 64889 [2]
Given Kudos: 426
Location: Pune, India
Send PM
Re: If the least common multiple of integers x and y is 840, [#permalink] New post   04 Oct 2016, 02:55
2
Kudos
Expert Reply
acegmat123 wrote:
If there are three numbers x,y,z

Can we say that,

x*y*z=LCM*GCD^2 ??


Sent from my iPhone using GMAT Club Forum mobile app


No, not correct.
GCF is only that which is common between all three.
LCM takes into account that which is common between two numbers but not all three as well. That is counted only once in the LCM.

For example:

12, 20, 30

12 = 2*2*3
20 = 2*2*5
30 = 2*3*5

LCM = 2*2*3*5 = 60
GCF = 2
User avatar
B
acegmat123
Manager
Manager
Joined: 28 Jun 2016
Posts: 153
Own Kudos [?]: 190 [0]
Given Kudos: 99
Location: Canada
Concentration: Operations, Entrepreneurship
Send PM
Re: If the least common multiple of integers x and y is 840, [#permalink] New post   04 Oct 2016, 04:53
Thank you Karishma. Now I understood.

It works only if GCF of three numbers is equal to GCF of any two numbers.

6, 10 and 14


Sent from my iPhone using GMAT Club Forum mobile app
User avatar
G
Basshead
Director
Director
Joined: 09 Jan 2020
Posts: 967
Own Kudos [?]: 223 [1]
Given Kudos: 434
Location: United States
Send PM
Re: If the least common multiple of integers x and y is 840, [#permalink] New post   22 Oct 2020, 03:35
1
Bookmarks
If the least common multiple of integers x and y is 840, what is the value of x?

(1) The greatest common factor of x and y is 56.

We know the LCM AND GCF; however, we are still not able to determine x and y. We only can determine the product of xy. Insufficient.

(2) y = 168

We know the LCM of x and y is 840. Statement 2 tells us y = 168. However, we still can't determine x.

(1&2) Product of xy = LCM of xy * GCF of xy = 840 * 56 = 2=47,040.

47,040 / 168 = 280.

x = 280. Statement 1 and 2 combined is sufficient.
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32642
Own Kudos [?]: 821 [0]
Given Kudos: 0
Send PM
Re: If the least common multiple of integers x and y is 840, [#permalink] New post   15 Jun 2023, 18:31
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.
GMAT Club Bot
gmatclubot
Re: If the least common multiple of integers x and y is 840, [#permalink]
15 Jun 2023, 18:31
   1   2 
Moderator:
Bunuel
Math Expert
92901 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions