Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 18 Jul 2019, 14:44

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

If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 56257
If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic  [#permalink]

Show Tags

New post 21 Jun 2019, 00:33
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

78% (01:07) correct 22% (01:12) wrong based on 45 sessions

HideShow timer Statistics


If the LCM of two integers a, b (where b> a and a>1) is a*b, then which of the following can not be true?

A. Both a and b can be Prime Numbers.
B. Both a and b can be consecutive integers.
C. All Prime factors of a must be Prime factors of b.
D. a and b do not share any Prime factors.
E. a and b do not have a common factor

_________________
Senior Manager
Senior Manager
avatar
G
Joined: 22 Nov 2018
Posts: 478
Location: India
GMAT 1: 640 Q45 V35
GMAT 2: 660 Q48 V33
GMAT ToolKit User Premium Member CAT Tests
Re: If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic  [#permalink]

Show Tags

New post 21 Jun 2019, 00:43
Bunuel wrote:
If the LCM of two integers a, b (where b> a and a>1) is a*b, then which of the following can not be true?

A. Both a and b can be Prime Numbers.
B. Both a and b can be consecutive integers.
C. All Prime factors of a must be Prime factors of b.
D. a and b do not share any Prime factors.
E. a and b do not have a common factor


a*b=LCM(a,b)*HCF(a,b)
As per stem HCF = 1; So A,B,D,E are ruled out. IMO C
_________________
Give +1 kudos if this answer helps..!!
Director
Director
avatar
G
Joined: 20 Jul 2017
Posts: 544
Location: India
Concentration: Entrepreneurship, Marketing
WE: Education (Education)
Re: If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic  [#permalink]

Show Tags

New post 21 Jun 2019, 01:32
1
Bunuel wrote:
If the LCM of two integers a, b (where b> a and a>1) is a*b, then which of the following can not be true?

A. Both a and b can be Prime Numbers.
B. Both a and b can be consecutive integers.
C. All Prime factors of a must be Prime factors of b.
D. a and b do not share any Prime factors.
E. a and b do not have a common factor


LCM of 2 numbers a & b = a*b is only possible if a & b have no common factors
or HCF(a, b) = 1

A. Both a and b can be Prime Numbers. - TRUE (No 2 prime numbers have common factors)
B. Both a and b can be consecutive integers. - TRUE (No 2 consecutive integers will have any common factors. Eg: (2, 3), (5, 6), (10, 11) etc.)
C. All Prime factors of a must be Prime factors of b. - NOT TRUE (There can't be any common factors, Either prime or non prime)
D. a and b do not share any Prime factors. - TRUE (There can't be any common factors)
E. a and b do not have a common factor - TRUE (As of D)

IMO Option C

Pls Hit Kudos if you like the solution
ISB School Moderator
User avatar
G
Joined: 08 Dec 2013
Posts: 528
Location: India
Concentration: Nonprofit, Sustainability
GMAT 1: 630 Q47 V30
WE: Operations (Non-Profit and Government)
Reviews Badge CAT Tests
Re: If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic  [#permalink]

Show Tags

New post 21 Jun 2019, 02:17
1
Dillesh4096, hello;

I'm a little confused with Statement E.
There is a possibility that 7 and 4 are the numbers and they have a common factor, 1. Kindly help!


Dillesh4096 wrote:
Bunuel wrote:
If the LCM of two integers a, b (where b> a and a>1) is a*b, then which of the following can not be true?

A. Both a and b can be Prime Numbers.
B. Both a and b can be consecutive integers.
C. All Prime factors of a must be Prime factors of b.
D. a and b do not share any Prime factors.
E. a and b do not have a common factor


LCM of 2 numbers a & b = a*b is only possible if a & b have no common factors
or HCF(a, b) = 1

A. Both a and b can be Prime Numbers. - TRUE (No 2 prime numbers have common factors)
B. Both a and b can be consecutive integers. - TRUE (No 2 consecutive integers will have any common factors. Eg: (2, 3), (5, 6), (10, 11) etc.)
C. All Prime factors of a must be Prime factors of b. - NOT TRUE (There can't be any common factors, Either prime or non prime)
D. a and b do not share any Prime factors. - TRUE (There can't be any common factors)
E. a and b do not have a common factor - TRUE (As of D)

IMO Option C

Pls Hit Kudos if you like the solution

_________________
Kindly drop a '+1 Kudos' if you find this post helpful.

GMAT Math Book


-I never wanted what I gave up
I never gave up what I wanted-
Director
Director
avatar
G
Joined: 20 Jul 2017
Posts: 544
Location: India
Concentration: Entrepreneurship, Marketing
WE: Education (Education)
Re: If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic  [#permalink]

Show Tags

New post 21 Jun 2019, 02:41
[quote="LeoN88"]Dillesh4096, hello;

I'm a little confused with Statement E.
There is a possibility that 7 and 4 are the numbers and they have a common factor, 1. Kindly help!


Hi LeoN88

It looks ambiguous as 1 is a common factor. I guess Option E should've been a and b do not have a common factor other than 1

Between option C & E, i think we should choose C

Guess, knowing the source will help further.

Bunuel Pls Guide
GMAT Club Bot
Re: If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic   [#permalink] 21 Jun 2019, 02:41
Display posts from previous: Sort by

If the LCM of two integers a, b (where b> a and a>1) is a*b, then whic

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





cron

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