GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video

It is currently 18 Feb 2020, 06:10

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.

Close

Request Expert Reply

Confirm Cancel

What is the LCM of x and 12?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Intern
Intern
avatar
B
Joined: 16 Apr 2009
Posts: 14
What is the LCM of x and 12?  [#permalink]

Show Tags

New post 20 Dec 2012, 22:16
1
4
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

40% (01:48) correct 60% (01:38) wrong based on 177 sessions

HideShow timer Statistics

What is the LCM of x and 12?

(1) The Least Common Multiple of x and 9 is 45?
(2) The Least Common Multiple of x and 4 is 20?
Most Helpful Community Reply
Intern
Intern
User avatar
Status: Edge of Extinction
Joined: 09 Sep 2012
Posts: 35
Re: What is the LCM of x and 12?  [#permalink]

Show Tags

New post 21 Dec 2012, 00:11
4
2
What is the LCM of x and 12?

(1) The Least Common Multiple of x and 9 is 45?
(2) The Least Common Multiple of x and 4 is 20?


(1)
Prime factors of 9 = 3X3; Prime factors of x = a.b.c...(say)
Prime factors of 45 = 5X3X3
So x = {5, 15, 45}
LCM of x and 12 = {60, 60, 180}
Hence INSUFFICIENT

(2)
Prime factors of 4 = 2X2; Prime factors of x = u.v.w...(say)
Prime factors of 20 = 5X2X2
So x = {5, 10, 20}
LCM of x and 12 = {60, 60, 60}, i.e. 60
Hence SUFFICIENT

Since (2) by itself is sufficient, hence (B) is the correct answer.

Thanks for sharing. :)
General Discussion
Intern
Intern
avatar
B
Joined: 16 Apr 2009
Posts: 14
Re: What is the LCM of x and 12?  [#permalink]

Show Tags

New post 21 Dec 2012, 01:03
Zenverse wrote:
What is the LCM of x and 12?

(1) The Least Common Multiple of x and 9 is 45?
(2) The Least Common Multiple of x and 4 is 20?


(1)
Prime factors of 9 = 3X3; Prime factors of x = a.b.c...(say)
Prime factors of 45 = 5X3X3
So x = {5, 15, 45}
LCM of x and 12 = {60, 60, 180}
Hence INSUFFICIENT

(2)
Prime factors of 4 = 2X2; Prime factors of x = u.v.w...(say)
Prime factors of 20 = 5X2X2
So x = {5, 10, 20}
LCM of x and 12 = {60, 60, 60}, i.e. 60
Hence SUFFICIENT

Since (2) by itself is sufficient, hence (B) is the correct answer.

Thanks for sharing. :)


Thanks to you as well for the reply..
Intern
Intern
User avatar
Joined: 24 Apr 2012
Posts: 44
Re: What is the LCM of x and 12?  [#permalink]

Show Tags

New post 21 Dec 2012, 03:04
2
Ans:

from 1st statement x could be 5,15,45 so l.c.m of (5,12)=60 l.c.m(15,12)=60 and l.c.m(45,12)=180 not sufficient. From 2nd statement x could be 5,10,20 so l.c.m(5,12)=60 l.c.m(10,12)=60 l.c.m(20,12)=60 , the answer is (B). :)
Manager
Manager
User avatar
P
Status: wake up with a purpose
Joined: 24 Feb 2017
Posts: 173
Concentration: Accounting, Entrepreneurship
GMAT ToolKit User Premium Member
What is the LCM of x and 12?  [#permalink]

Show Tags

New post 02 Jul 2019, 09:52
Drik wrote:
What is the LCM of x and 12?

(1) The Least Common Multiple of x and 9 is 45?
(2) The Least Common Multiple of x and 4 is 20?


What is the theory behind this kind of question? I don't understand the number picking here. Would you please show me other number picking? Bunuel
_________________
If people are NOT laughing at your GOALS, your goals are SMALL.
Rice (Jones) School Moderator
User avatar
P
Joined: 18 Jun 2018
Posts: 334
Location: United States (AZ)
Concentration: Finance, Healthcare
GMAT 1: 620 Q45 V31
GPA: 3.36
What is the LCM of x and 12?  [#permalink]

Show Tags

New post 02 Jul 2019, 10:38
2
RashedVai Hello, I can help.This question is testing your knowledge of number properties, LCM to be specific. The LCM tells us the unique prime factors shared by a set of numbers.

Since we are asked to find the LCM of x and 12, we know 12 = \(2^{2}\) x \(3\), so we need to find x
St 1: LCM(x,9) = 45
45 = \(3^{2}\) x \(5\)
9 = \(3^{2}\), therefore x could be 5, 15 (\(3\) x \(5\)) or even 45 (important to note: the LCM of a factor and its multiple = multiple).
You will get different answers for LCM(x,12) when you test these numbers, therefore statement one is insufficient
St 2: LCM(x,4) = 20
20 = \(2^{2}\) x \(5\)
4 = \(2^{2}\), therefore x could be 5, 10 (\(2\) x \(5\)) or 20 (recall the note above?). Test these numbers for LCM(x,12) and you will get a unique value (60) every time, therefore statement 2 is sufficient and the right answer is B.

Hope this helps. Feel free to reach out if you still have doubts.

Cheers!
Intern
Intern
avatar
Joined: 22 Jul 2019
Posts: 1
Re: What is the LCM of x and 12?  [#permalink]

Show Tags

New post 29 Nov 2019, 08:16
priyamne wrote:
Ans:

from 1st statement x could be 5,15,45 so l.c.m of (5,12)=60 l.c.m(15,12)=60 and l.c.m(45,12)=180 not sufficient. From 2nd statement x could be 5,10,20 so l.c.m(5,12)=60 l.c.m(10,12)=60 l.c.m(20,12)=60 , the answer is (B). :)



Thanks..this was helpful !!
GMAT Club Bot
Re: What is the LCM of x and 12?   [#permalink] 29 Nov 2019, 08:16
Display posts from previous: Sort by

What is the LCM of x and 12?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne