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

It is currently 17 Jan 2019, 19:46

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
Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
  • The winning strategy for a high GRE score

     January 17, 2019

     January 17, 2019

     08:00 AM PST

     09:00 AM PST

    Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL.
  • 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.

If mn = 3(m + 1) + n and m and n are integers

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

Hide Tags

 
SVP
SVP
User avatar
Joined: 06 Sep 2013
Posts: 1705
Concentration: Finance
GMAT ToolKit User
If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 20 Sep 2013, 15:05
3
6
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

63% (01:45) correct 37% (01:33) wrong based on 377 sessions

HideShow timer Statistics

If mn = 3(m + 1) + n and m and n are integers, m could be any of the following values EXCEPT:

(A) 2
(B) 3
(C) 4
(D) 5
(E) 7
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52231
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 20 Sep 2013, 15:09
4
jlgdr wrote:
If mn = 3(m + 1) + n and m and n are integers, m could be any of the following values EXCEPT:

(A) 2
(B) 3
(C) 4
(D) 5
(E) 7


mn = 3(m + 1) + n
mn - n = 3(m + 1)
n = 3(m + 1)/(m-1)

n won't be an integer only if m = 5 (from the options).

Answer: D.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 04 Dec 2012
Posts: 6
Schools: ISB '15
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 22 Sep 2013, 04:00
jlgdr wrote:
If mn = 3(m + 1) + n and m and n are integers, m could be any of the following values EXCEPT:

(A) 2
(B) 3
(C) 4
(D) 5
(E) 7


Alternative way of looking at it

mn = 3(m+1) + n
n = 3(m+1)/(m-1)
n = 3[(m-1)+2)]/(m-1)
n = 3(1 + 2/(m-1))
n = 3 + 6/(m-1)

=> given answer choice - 1 should divide 6.

Only 5 does not satisfy the above condition.
Manager
Manager
User avatar
Joined: 03 Dec 2012
Posts: 204
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 15 Oct 2013, 06:24
This is how I solved the question mn=3(m+1)+n => mn= 3m+3 +n => mn-3m=n+3 => m(n-3)=n+3 => m=n+3/n-3 In this cast 7 fits the bill. Where am I going wrong Bunuel?
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 52231
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 15 Oct 2013, 07:52
1
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1823
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 23 Feb 2014, 21:37
1
mn = 3(m + 1) + n and m and n are integers-

Solved by placing the values directly from the options:

For m=2, 2n = 9 + n .......... OK
For m=3, 3n = 12 +n..........OK
For m=4, 4n = 15 + n..........OK
For m=5, 5n = 18 + n.......... 4n = 18... then n becomes a non-integer
So Answer = D = 5
_________________

Kindly press "+1 Kudos" to appreciate :)

Director
Director
User avatar
S
Affiliations: CrackVerbal
Joined: 03 Oct 2013
Posts: 533
Location: India
GMAT 1: 780 Q51 V46
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 23 Feb 2014, 22:13
jlgdr wrote:
If mn = 3(m + 1) + n and m and n are integers, m could be any of the following values EXCEPT:

(A) 2
(B) 3
(C) 4
(D) 5
(E) 7


Let us plug in:

m = 2 , 2(n) = 3(2 + 1) + n then n will be 9
m = 3, 3(n) = 3(4) + n, then n will be an integer
m = 4, 4(n) = 3(5) + n, then n will be an integer
m = 5, 5(n) = 3(6) + n, then n will be 18/4 (not an integer) (BINGO!)
m = 7, 7(n) = 3(8) + n, still n will be an integer

Answer is D.
_________________

For more info on GMAT and MBA, follow us on @AskCrackVerbal

Register for the Free GMAT Video Training Course : https://crackverbal.com/MBA-Through-GMAT-2019-Registration

Current Student
User avatar
B
Joined: 20 Jan 2017
Posts: 58
Location: United States (NY)
Schools: CBS '20 (A)
GMAT 1: 750 Q48 V44
GMAT 2: 610 Q34 V41
GPA: 3.92
Reviews Badge
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 16 Feb 2017, 04:23
\(mn = 3(m + 1) + n; mn=3m+3+n; mn-n=3m+3; n(m-1)=3m+3; n=\frac{3m+3}{m-1}\)
Plug in answer choices into the above equation:
(A) \(2 - n=\frac{(3*2+3)}{2-1}=9\)
(B) \(3 - n=\frac{(3*3+3)}{3-1}=6\)
(C) \(4 - n=\frac{(3*4+3)}{4-1}=5\)
(D) \(5 - n=\frac{(3*5+3)}{5-1}=\) not an integer
(E) \(7 - n=\frac{(3*7+3)}{7-1}=4\)

The correct answer is D.
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 21 Feb 2017, 09:22
1
jlgdr wrote:
If mn = 3(m + 1) + n and m and n are integers, m could be any of the following values EXCEPT:

(A) 2
(B) 3
(C) 4
(D) 5
(E) 7


We are given that mn = 3(m + 1) + n. Let’s simplify that equation:

mn = 3(m + 1) + n

mn - n = 3(m + 1)

n(m - 1) = 3(m + 1)

n = 3(m + 1)/(m - 1)

We can see that we can eliminate choices A and C since the denominators will be 1 and 3, respectively. Now let’s check the other answer choices:

B) If m = 3, then n = 3(3+1)/(3-1) = 12/2 = 6, which is an integer.

D) If m = 5, then n = 3(5+1)/(5-1) = 18/4 = 4.5, which is NOT an integer.

Thus choice D is the correct answer.

Answer: D
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 9419
Premium Member
Re: If mn = 3(m + 1) + n and m and n are integers  [#permalink]

Show Tags

New post 31 Dec 2018, 13:44
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 Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

GMAT Club Bot
Re: If mn = 3(m + 1) + n and m and n are integers &nbs [#permalink] 31 Dec 2018, 13:44
Display posts from previous: Sort by

If mn = 3(m + 1) + n and m and n are integers

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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®.