GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 18 Jan 2019, 20:20

### 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

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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### Free GMAT Strategy Webinar

January 19, 2019

January 19, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
• ### FREE Quant Workshop by e-GMAT!

January 20, 2019

January 20, 2019

07:00 AM PST

07:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.

# If r and s are positive integers, is the least common multiple of r an

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

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6815
GMAT 1: 760 Q51 V42
GPA: 3.82
If r and s are positive integers, is the least common multiple of r an  [#permalink]

### Show Tags

04 Jan 2017, 04:14
00:00

Difficulty:

25% (medium)

Question Stats:

81% (01:27) correct 19% (01:16) wrong based on 103 sessions

### HideShow timer Statistics

If r and s are positive integers, is the least common multiple of r and s equal to the product of r and s?

1) r and s are consecutive odd numbers
2) r=s+2

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Joined: 13 Apr 2010
Posts: 89
Re: If r and s are positive integers, is the least common multiple of r an  [#permalink]

### Show Tags

04 Jan 2017, 07:08
MathRevolution wrote:
If r and s are positive integers, is the least common multiple of r and s equal to the product of r and s?

1) r and s are consecutive odd numbers
2) r=s+2

LCM of two numbers is equal to the product of that two numbers when the two numbers don't share any common prime factors.
Given that r and s are positive integers .

statement 1 : r and s are consecutive odd integers . As consecutive odd integers don't share any common prime factors. We can be sure that LCM will be equal to the product of that two numbers .
Statement 1 is sufficient .
Ex. 3 and 5 / 21 and 23 / 97 and 99 etc .

statement 2, r = s +2
r can be 8 and s can be 6 : in this case the LCM is not equal to product (LCM = 24 and product = 48 )
or
r can be 5 and s can be 3 : in this case the LCM = product = 15

Answer is A .
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6815
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: If r and s are positive integers, is the least common multiple of r an  [#permalink]

### Show Tags

06 Jan 2017, 01:39
==> In the original condition, there are 2 variables (r, s), and therefore C is most likely to be the answer. By solving con 1) and con 2), it is yes, hence sufficient. Therefore, C is the answer. However, since it is an integer question, one of the key questions, if you apply CMT 4(A) on con 1), you get yes and hence it is sufficient.

Therefore, the answer is A.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Joined: 01 Nov 2016
Posts: 66
Concentration: Technology, Operations
Re: If r and s are positive integers, is the least common multiple of r an  [#permalink]

### Show Tags

09 May 2017, 15:42
sb0541 wrote:
consecutive odd integers don't share any common prime factors

Wish I had known this, I would have been able to solve the problem
Re: If r and s are positive integers, is the least common multiple of r an &nbs [#permalink] 09 May 2017, 15:42
Display posts from previous: Sort by

# If r and s are positive integers, is the least common multiple of r an

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

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.