BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

two prime numbers

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

two prime numbers

by sanju09 » Tue Oct 18, 2011 5:11 am
If the least common multiple of two prime numbers x and y is 10, where x > y, then what is the value of 2 x + y?
(A) 7
(B) 9
(C) 11
(D) 12
(E) 21
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Tue Oct 18, 2011 5:28 am
sanju09 wrote:If the least common multiple of two prime numbers x and y is 10, where x > y, then what is the value of 2 x + y?
10 = 1*10 = 2*5

Hence, the prime numbers must be 2 and 5.
As x > y, y = 2 and x = 5

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

The correct answer is D.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 am
Location: Utrecht, The Netherlands
Thanked: 318 times
Followed by:52 members

by neelgandham » Tue Oct 18, 2011 7:12 am
If the least common multiple of two prime numbers x and y is 10, where x > y, then what is the value of 2 x + y?

x,y are definitely less than 10 and are prime numbers. 2,3,5,7 are the only prime numbers below 10, of which 2,5 are multiples of 10, that makes x,y = 2,5 or 5,2.

x > y (from the question) => x = 5, and y = 2 => 2x+y =[spoiler] 2*5+2 = 12 [/spoiler]

Answer: optionD
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Top
Post new topic Post Reply
• Page 1 of 1