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

It is currently 24 Jun 2018, 00:19

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

Events & Promotions in June
Open Detailed Calendar

If m and n are positive integers, what is the value of m + n?

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

Hide Tags

Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 46303
If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 07:17
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

73% (00:40) correct 27% (00:39) wrong based on 90 sessions

HideShow timer Statistics

1 KUDOS received
Retired Moderator
avatar
B
Status: On a mountain of skulls, in the castle of pain, I sit on a throne of blood.
Joined: 30 Jul 2013
Posts: 351
GMAT ToolKit User Reviews Badge
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 08:16
1
Bunuel wrote:
If m and n are positive integers, what is the value of m + n?

(1) m/n = 7/10

(2) The greatest common factor of m and n is 1.


Kudos for a correct solution.


m+n=?

1. Not Sufficient
m=7n/10
m+n=7n/10 + n =17n/10

2. Not Sufficient
Tells us that m and n are co primes.

1 and 2.Sufficient
m and n are co primes. So m=7 and n=10 and m+n=17


Answer: C
Manager
Manager
User avatar
S
Status: Just redeemed Kudos for GMAT Club Test !!
Joined: 14 Sep 2013
Posts: 93
Location: Bangladesh
GMAT 1: 530 Q40 V23
GPA: 3.56
WE: Analyst (Commercial Banking)
GMAT ToolKit User Premium Member
If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post Updated on: 28 Oct 2015, 09:05
Quote:
If m and n are positive integers, what is the value of m + n?
(1) m/n = 7/10
(2) The greatest common factor of m and n is 1.

Kudos for a correct solution.


Statement 1 says m/n = 7/10. There are multiple values of m & n e.g. m/n = 14/20 = 7/10 OR 21/30 = 7/10 etc. NOT sufficient.
Statement 2 says m & n have no common factor except 1. However, no specific value of m & n is provided. NOT sufficient.

Combining 1 & 2
As there is no common factor except 1, the only possible values for m & n are 7 & 10 respectively. So m+n = 17. Sufficient.

Option (C) wins.
_________________

______________
KUDOS please, if you like the post or if it helps :-)
"Giving kudos" is a decent way to say "Thanks"

Master with structure - Numerical comparison [source: economist.com] https://gmatclub.com/forum/master-with-structure-numerical-comparison-233657.html#p1801987


Originally posted by musunna on 28 Oct 2015, 08:27.
Last edited by musunna on 28 Oct 2015, 09:05, edited 1 time in total.
1 KUDOS received
Manager
Manager
User avatar
Joined: 13 Apr 2015
Posts: 75
Concentration: General Management, Strategy
GMAT 1: 620 Q47 V28
GPA: 3.25
WE: Project Management (Energy and Utilities)
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 08:37
1
Ans should be C.

The question does not asks the exact values of M & N, It asks their sum.what is M + N = ...? ( certainly some +ve Integer as M & N are +ve Integers )

Statement 1 -> M / N = 7 / 10 , As this is a ratio, exact values of M & N tend to vary accordingly...

If M = 7, N would be 10.
If M = 14, N would be 20.
If M = 70, N would be 100. Similarlly infinite values exists for M & N.

Hence Insufficient.

Statement 2 -> The GCD of M & N is 1. This signifies that M & N have no common divisor apart from 1. That is M & N could be a combination of different primes such as 2 & 3, 3 & 5 or 7 & 11 and so on.

Hence insufficient.

Combining both Statements,7 and 10 are the only values of M & N that satisfies both conditions. Hence suficcient.

Note:- If the question would have asked M - N ( a potential trap ), then the answer would have been E, as in that case exact values of Both M & N would have been required.
1 KUDOS received
Manager
Manager
User avatar
S
Status: Just redeemed Kudos for GMAT Club Test !!
Joined: 14 Sep 2013
Posts: 93
Location: Bangladesh
GMAT 1: 530 Q40 V23
GPA: 3.56
WE: Analyst (Commercial Banking)
GMAT ToolKit User Premium Member
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 09:00
1
Thanks goldfinchmonster Correct you are. Option (c) is the right answer.
I visualized correctly but mess up while explaining :cry:

Now corrected.
_________________

______________
KUDOS please, if you like the post or if it helps :-)
"Giving kudos" is a decent way to say "Thanks"

Master with structure - Numerical comparison [source: economist.com] https://gmatclub.com/forum/master-with-structure-numerical-comparison-233657.html#p1801987

Expert Post
1 KUDOS received
SVP
SVP
User avatar
P
Joined: 08 Jul 2010
Posts: 2115
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 09:48
1
Bunuel wrote:
If m and n are positive integers, what is the value of m + n?

(1) m/n = 7/10

(2) The greatest common factor of m and n is 1.


Kudos for a correct solution.


Question : m + n = ?

Statement 1: m/n = 7/10
Case 1: m = 7, n = 10 and m+n = 17
Case 2: m = 14, n = 20 and m+n = 34
Hence,
NOT SUFFICIENT

Statement 2: The greatest common factor of m and n is 1.
Case 1: m = 7, n = 10 and m+n = 17
Case 2: m = 4, n = 3 and m+n = 7
Hence,
NOT SUFFICIENT

Combining the two statements
m/n = 7/10
and GCD of m and n is 1 i.e. they must be co-prime to each other which is possible only when
m = 7 and n = 10
i.e. m+n = 17
SUFFICIENT

Answer: option C
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Current Student
User avatar
S
Joined: 28 Nov 2014
Posts: 895
Concentration: Strategy
Schools: Fisher '19 (M)
GPA: 3.71
Reviews Badge
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 28 Oct 2015, 13:46
If m and n are positive integers, what is the value of m + n?

(1) m/n = 7/10

(2) The greatest common factor of m and n is 1.

__________________________

m and n are positive integers. So, m and n can take the values 1,2,3.4.5,...........+infinity

ST 1: m/n = 7/10
Ratio is given. Therefore, a lot of values of m+n are possible. Insufficient.

ST 2: GCF (m,n) = 1
This means that both m and n are co prime to each other. Again, a lot of possibilities. Insufficient.

ST 1 + 2 :
m = 7 and n = 10 and both have GCF (7,10) = 1
On multiplying it with 2,3,4,5,6,... GCF will not be 1 any more.

So only 1 value is possible. m+n = 17

C should be the answer.
Director
Director
avatar
S
Joined: 12 Nov 2016
Posts: 776
Location: United States
Schools: Yale '18
GMAT 1: 650 Q43 V37
GRE 1: 315 Q157 V158
GPA: 2.66
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 17 Jul 2017, 19:18
Bunuel wrote:
If m and n are positive integers, what is the value of m + n?

(1) m/n = 7/10

(2) The greatest common factor of m and n is 1.


Kudos for a correct solution.


This is clearly C

Statement 1

m/n =7/10... could be 14/20 or several other values - as long as it reduces to 7/10

Statement 2

GCF of both is 1

could be 2 primes such as 5 and 7 or 2 other random numbers such 7 and 10

insuff

St 1 and St 2

In order for m/n=7/10 and the gcf to be 1 m and n cannot exceed 7 and 10= any larger that simplifies to that value would have a different gcf

C
Manager
Manager
avatar
S
Joined: 13 Mar 2013
Posts: 173
Location: United States
Concentration: Leadership, Technology
GPA: 3.5
WE: Engineering (Telecommunications)
Re: If m and n are positive integers, what is the value of m + n? [#permalink]

Show Tags

New post 11 Aug 2017, 06:55
silly mistake ..... forgot to use (2) while combining the statement
_________________

Regards ,

Re: If m and n are positive integers, what is the value of m + n?   [#permalink] 11 Aug 2017, 06:55
Display posts from previous: Sort by

If m and n are positive integers, what is the value of m + n?

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


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®.