NEW HERE? LEARN MORE
closeclose
Last visit was: 29 Apr 2024, 01:42 It is currently 29 Apr 2024, 01:42
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 two prime numbers x and y is 10, where

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92988
Own Kudos [?]: 619799 [3]
Given Kudos: 81626
Send PM
CAT Tests Forum Quiz Mode
If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   08 Jun 2016, 10:08
3
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

5% (low)

Question Stats:

87% (00:51) correct 13% (01:03) wrong based on 349 sessions
Hide Show timer Statistics
If the least common multiple of two prime numbers x and y is 10, where x > y, then the value of 2x + y is

A. 7
B. 9
C. 11
D. 12
E. 21
ShowHide Answer
Official Answer
D
Most Helpful Reply
User avatar
FacelessMan
Manager
Manager
Joined: 19 Dec 2015
Posts: 89
Own Kudos [?]: 395 [6]
Given Kudos: 13
Location: United States
Schools: Duke '19 Kenan-Flagler '19
GMAT 1: 720 Q50 V38
GPA: 3.8
WE:Information Technology (Computer Software)
Send PM
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   08 Jun 2016, 10:19
4
Kudos
2
Bookmarks
LCM of two prime numbers will basically be multiple of those numbers. LCM = 10 = 2*5, both of which are prime.

Now we know x>y, so x=5 and y =2.
2x+y = 2*5 + 2 = 10 + 2 = 12. Hence D.
General Discussion
User avatar
Divyadisha
Current Student
Joined: 18 Oct 2014
Posts: 680
Own Kudos [?]: 1763 [0]
Given Kudos: 69
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
Send PM
GMAT ToolKit User
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   08 Jun 2016, 10:30
Bunuel wrote:
If the least common multiple of two prime numbers x and y is 10, where x > y, then the value of 2x + y is

A. 7
B. 9
C. 11
D. 12
E. 21


Since both are prime numbers there are only two factors for each 1 and the number itself.

LCM of two prime numbers = multiplication of the numbers

10= 2*5 or 5*2

But its given that x>y, hence x=5 and y =2

2x+y= 2*5 +2= 12

D is the answer
avatar
B
OptimusPrepJanielle
SVP
SVP
Joined: 06 Nov 2014
Posts: 1798
Own Kudos [?]: 1368 [0]
Given Kudos: 23
Send PM
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   09 Jun 2016, 03:54
Expert Reply
Bunuel wrote:
If the least common multiple of two prime numbers x and y is 10, where x > y, then the value of 2x + y is

A. 7
B. 9
C. 11
D. 12
E. 21


LCM (x,y) = 10 and both x an y are prime.
The only values of x and y can be 5 and 2 (x = 5 and y = 2)

2x + y = 2*5 + 2 = 12

Correct Option: D
User avatar
D
stonecold
Alum
Joined: 12 Aug 2015
Posts: 2282
Own Kudos [?]: 3133 [0]
Given Kudos: 893
Schools: Boston U '20 (M)
GRE 1: Q169 V154
Send PM
GMAT ToolKit User
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   29 Apr 2017, 22:00
Excellent Question.
Here is what i did on this one ->
Since x,y are primes and x>y---->
LCM(x,y) => Product of x*y

Hence 10=xy
10=> 2*5

Thus x=5 ans y=2

So 2x+y=> 12

SMASH THAT D
User avatar
L
BrentGMATPrepNow
GMAT Club Legend
GMAT Club Legend
Joined: 12 Sep 2015
Posts: 6818
Own Kudos [?]: 29988 [1]
Given Kudos: 799
Location: Canada
Send PM
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   29 Jun 2019, 09:56
1
Kudos
Expert Reply
Top Contributor
Bunuel wrote:
If the least common multiple of two prime numbers x and y is 10, where x > y, then the value of 2x + y is

A. 7
B. 9
C. 11
D. 12
E. 21


2 and 5 are the only PRIME numbers with an LCM of 10
Since we're told x > y, we can conclude that x = 5 and y = 2

So, 2x + y = 2(5) + 2 = 12

Answer: D

Cheers,
Brent
User avatar
D
BrushMyQuant
Tutor
Joined: 05 Apr 2011
Status:Tutor - BrushMyQuant
Posts: 1778
Own Kudos [?]: 2095 [0]
Given Kudos: 100
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 700 Q51 V31
GPA: 3
WE:Information Technology (Computer Software)
Send PM
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   27 Oct 2022, 11:44
Expert Reply
Top Contributor
Theory: If two numbers are co-prime (have no common factor apart from 1) then their LCM = product of those numbers

If the least common multiple of two prime numbers x and y is 10
Simce x and y are prime so they will have only one common factor between them which is 1
=> x and y are co-prime numbers
So, LCM(x,y) = x*y = 10
So, x and y can be 2 and 5
But we know that x > y
=> x= 5 and y =2

2x + y = 2*5 + 2 = 12

So, Answer will be D
Hope it helps!

To learn more about LCM and GCD watch these videos



User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32729
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: If the least common multiple of two prime numbers x and y is 10, where [#permalink] New post   07 Dec 2023, 05:41
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 two prime numbers x and y is 10, where [#permalink]
07 Dec 2023, 05:41
Moderators:
Bunuel
Math Expert
92987 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 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