GMAT Question of the Day: Daily via email | Daily via Instagram New to GMAT Club? Watch this Video
close
It is currently 21 Jun 2021, 09:00
Register
GMAT Club Tests
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
Which of the following CANNOT be the least common multiple of two posi
10 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
Tags:
Find Similar Topics 

Show Tags
Hide Tags

User avatar
PareshGmat
SVP
SVP
Joined: 27 Dec 2012
Status:The Best Or Nothing
Posts: 1664
Location: India
Concentration: General Management, Technology
WE:Information Technology (Computer Software)
Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  09 Sep 2014, 01:09
5
Kudos
43
Bookmarks
Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

67% (00:58) correct 33% (01:01) wrong based on 899 sessions

Hide Show timer Statistics

Which of the following CANNOT be the least common multiple of two positive integers x and y?

(A) xy
(B) x
(C) y
(D) x - y
(E) x + y
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.
Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
Most Helpful Expert Reply
User avatar
V
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 77331
Premium Member CAT Tests Top Member of the Month
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  09 Sep 2014, 06:10
6
Kudos
14
Bookmarks
Expert Reply
PareshGmat wrote:
Which of the following CANNOT be the least common multiple of two positive integers x and y?

(A) xy
(B) x
(C) y
(D) x - y
(E) x + y

Should be very easy...... :)


The least common multiple of two positive integers cannot be less than either of them. Therefore, since x - y is less than x, it cannot be the LCM of a x and y.

Answer: D.

Similar questions to practice:
which-of-the-following-cannot-be-the-greatest-common-divisor-108865.html
which-of-the-following-cannot-be-the-least-common-multiple-167145.html
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
General Discussion
User avatar
V
EMPOWERgmatRichC
EMPOWERgmat Instructor
Joined: 19 Dec 2014
Status:GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Posts: 19216
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
CAT Tests
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  17 Jan 2016, 20:24
3
Kudos
3
Bookmarks
Expert Reply
Hi All,

This question is really just a test of your overall understanding of the concept of 'least common multiple.' You don't have to do any fancy math to get the correct answer (and the design of the answer choices helps to avoid a certain amount of thinking/work).

The Least Common Multiple between two integers is the smallest number that is a positive multiple of BOTH integers.

For example:

The LCM of 2 and 3 is 6
The LCM of 2 and 4 is 4
The LCM of 3 and 5 is 15

Notice how the LCM is ALWAYS greater than OR equal to both of the integers involved. Knowing THAT rule, you can quickly deduce which answer choice CANNOT be the LCM of 2 distinct positive integers....

Final Answer:
Show Spoiler
D


GMAT assassins aren't born, they're made,
Rich
_________________
Contact Rich at: Rich.C@empowergmat.com
Image

The Course Used By GMAT Club Moderators To Earn 750+

souvik101990 Score: 760 Q50 V42 ★★★★★
ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★
Signature Read More
User avatar
D
stonecold
Current Student
Joined: 12 Aug 2015
Posts: 2458
Schools: Boston U '20 (M)
GRE 1: Q169 V154
GMAT ToolKit User
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  29 Apr 2017, 16:18
LCM must be greater than or equal to all the involved numbers.
Hence LCM can never be x-y as it is less than x.

Additionally => LCM(x,y) for x>y must lie in the bound => [ x,x*y]


Smash that D
_________________
Give me a hell yeah ...!!!!!

MBA Recruiting:- EMPLOYMENT AND SALARY STATISTICS AT TOP B-SCHOOLS IN THE US! (2018)
MBA Financing:- INDIAN PUBLIC BANKS vs PRODIGY FINANCE!

Getting into HOLLYWOOD with an MBA!
The MOST AFFORDABLE MBA programs!
STONECOLD's BRUTAL Mock Tests for GMAT-Quant(700+)
AVERAGE GRE Scores At The Top Business Schools!
Signature Read More
User avatar
G
JeffTargetTestPrep
Target Test Prep Representative
Joined: 04 Mar 2011
Status:Head GMAT Instructor
Affiliations: Target Test Prep
Posts: 2792
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  26 Feb 2018, 09:58
1
Kudos
1
Bookmarks
Expert Reply
PareshGmat wrote:
Which of the following CANNOT be the least common multiple of two positive integers x and y?

(A) xy
(B) x
(C) y
(D) x - y
(E) x + y


Since the difference of x - y is less than x, the quantity x - y can’t be a multiple of x. Thus, it can’t be the least common multiple (LCM) of x and y.

(Note: We think the correct answer is intended to be D for the reason stated above, but choice E is also correct since x + y can’t be the LCM of x and y either. We can prove this by contradiction:

Let’s suppose that x + y is the LCM of x and y. We see that x and y can’t be equal, otherwise either x or y (not their sum) will be the LCM of x and y. Now let’s say that x < y. Since we suppose that x + y is the LCM of x and y, y, the larger of the two numbers, can’t be the LCM of x and y. But the LCM of x and y must be the a multiple of y, so it has to be at least 2y (if it can’t be y). Here is the contradiction: 2y > x + y since y > x. So it’s impossible to have x + y as the LCM of x and y.)

Answer: D
_________________

★ ★ ★ ★ ★   350 REVIEWS

5-STAR RATED ONLINE GMAT QUANT SELF STUDY COURSE

NOW WITH GMAT VERBAL (Pre-Launch)

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

Signature Read More
User avatar
V
stne
VP
VP
Joined: 27 May 2012
Posts: 1339
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  23 Aug 2018, 06:51
2
Kudos
PareshGmat wrote:
Which of the following CANNOT be the least common multiple of two positive integers x and y?

(A) xy
(B) x
(C) y
(D) x - y
(E) x + y


Got the answer , but I am having a hard time finding examples for option E. Can anybody give examples of 2 integers where adding them leads to their LCM. Tried a couple of pairs couldn't get the answer , hence querying. Thanks.
_________________
- Stne
Signature Read More
avatar
G
chrtpmdr
Manager
Manager
Joined: 23 Jul 2019
Posts: 237
Schools: HSG MBF "23 (A), UniBocconi MFin "23 (A)
GMAT 1: 730 Q46 V45
GPA: 3.9
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  26 Oct 2019, 23:38
So E) is true as well?

I knew that D) must be the answer but somehow could not prove E) as right either.
The other ones were easy elimination!
_________________
Let's get some
Signature Read More
avatar
B
astiles67
Intern
Intern
Joined: 02 Mar 2020
Posts: 20
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  30 May 2021, 14:27
Bunuel wrote:
PareshGmat wrote:
Which of the following CANNOT be the least common multiple of two positive integers x and y?

(A) xy
(B) x
(C) y
(D) x - y
(E) x + y

Should be very easy...... :)


The least common multiple of two positive integers cannot be less than either of them. Therefore, since x - y is less than x, it cannot be the LCM of a x and y.

Answer: D.

Similar questions to practice:
http://gmatclub.com/forum/which-of-the- ... 08865.html
http://gmatclub.com/forum/which-of-the- ... 67145.html


2-2=0

0 is a multiple of every number, and the LCM of 2 and 2
avatar
B
astiles67
Intern
Intern
Joined: 02 Mar 2020
Posts: 20
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  30 May 2021, 14:56
The least common multiple of two positive integers cannot be less than either of them. Therefore, since x - y is less than x, it cannot be the LCM of a x and y.

Answer: D.

Similar questions to practice:
http://gmatclub.com/forum/which-of-the- ... 08865.html
http://gmatclub.com/forum/which-of-the- ... 67145.html[/quote]

2-2=0

0 is a multiple of every number, and the LCM of 2 and 2[/quote]

Not sure what you are trying to say there. Care to elaborate? Thanks.[/quote]

Yep - isn't 0 a multiple of every number?

TF, if X=Y ie 2 and 2, 2-2=0 which is then LCM of X=2 and Y=2
User avatar
V
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 77331
Premium Member CAT Tests Top Member of the Month
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink] New post  30 May 2021, 14:58
Expert Reply
astiles67 wrote:
The least common multiple of two positive integers cannot be less than either of them. Therefore, since x - y is less than x, it cannot be the LCM of a x and y.

Answer: D.

Similar questions to practice:
http://gmatclub.com/forum/which-of-the- ... 08865.html
http://gmatclub.com/forum/which-of-the- ... 67145.html


2-2=0

0 is a multiple of every number, and the LCM of 2 and 2[/quote]

Not sure what you are trying to say there. Care to elaborate? Thanks.[/quote]

Yep - isn't 0 a multiple of every number?

TF, if X=Y ie 2 and 2, 2-2=0 which is then LCM of X=2 and Y=2[/quote]

The least common multiple of two integers a and b is the smallest positive integer that is divisible by both a and b.
_________________
New to the GMAT CLUB Forum?

My Signature Questions' Collection:


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics
Signature Read More
GMAT Club Bot
gmatclubot
Re: Which of the following CANNOT be the least common multiple of two posi [#permalink]
30 May 2021, 14:58
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
chetan2u
Math Expert
10016 posts
Bunuel
Math Expert
77331 posts
yashikaaggarwal
Senior Moderator - Masters Forum
2544 posts
generis
Senior SC Moderator
4818 posts

cron

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