Find all School-related info fast with the new School-Specific MBA Forum

It is currently 28 Jul 2015, 00:42
GMAT Club Tests

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
4 KUDOS received
Moderator
Moderator
User avatar
Status: battlecruiser, operational...
Joined: 25 Apr 2010
Posts: 984
Schools: Carey '16
GMAT 1: Q V
Followers: 11

Kudos [?]: 122 [4] , given: 71

Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an [#permalink] New post 31 Aug 2010, 13:04
4
This post received
KUDOS
11
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

54% (01:41) correct 46% (00:46) wrong based on 571 sessions
Is n an integer?

(1) n^2 is an integer

(2) n^(1/2) is an integer
[Reveal] Spoiler: OA

_________________

GMAT Club Premium Membership - big benefits and savings


Last edited by Bunuel on 05 Apr 2012, 02:48, edited 1 time in total.
Edited the question and added the OA
Expert Post
7 KUDOS received
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28721
Followers: 4572

Kudos [?]: 47131 [7] , given: 7108

Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an [#permalink] New post 31 Aug 2010, 13:18
7
This post received
KUDOS
Expert's post
1
This post was
BOOKMARKED
vwjetty wrote:
Is n an integer?

(1) n^2 is an integer

(2) n^(1/2) is an integer

Please explain. Thanks.


Is n an integer?

(1) n^2 is an integer --> not sufficient, as if \(n^2=4\) answer is YES, but if \(n^2=3\) answer is NO.

(2) n^(1/2) is an integer --> \(\sqrt{n}=integer\) --> \(n=integer^2=integer\). Sufficient.

Answer: B.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Moderator
Moderator
User avatar
Status: battlecruiser, operational...
Joined: 25 Apr 2010
Posts: 984
Schools: Carey '16
GMAT 1: Q V
Followers: 11

Kudos [?]: 122 [0], given: 71

Re: N [#permalink] New post 31 Aug 2010, 13:20
oh wow. i feel dumb now. for some reason i was thinking something else. tricky tricky. thx. +1 kudo's good sir.
_________________

GMAT Club Premium Membership - big benefits and savings

Manager
Manager
avatar
Joined: 08 Sep 2011
Posts: 75
Concentration: Finance, Strategy
Followers: 3

Kudos [?]: 2 [0], given: 5

Re: OG 11th edition [#permalink] New post 12 Dec 2011, 12:31
Answer is indeed B.

stmt 1: says that n^2 is an integer. So n could be 4, which n^16 or n could be 5.477 and n^2 would be 30. This gives us two different options so insuff

stmt 2: says that sqrt n is an integer. that means n is the square of an (or integer x integer) which will always give you an integer. suff
Intern
Intern
avatar
Joined: 14 Sep 2010
Posts: 22
Followers: 0

Kudos [?]: 7 [0], given: 4

Re: OG 11th edition [#permalink] New post 23 Dec 2011, 00:16
Is n an integer?

(1) n^2 is an integer

(2) sqrt(n) is an integer

S1: If n^2 is an integer, is n an integer?

Is n rational or irrational?

If rational, then n can be expressed as p/q,
where p and q are non-zero integers.
Further, if n^2 = (p/q)^2 is an integer, n = p/q is an integer.

If irrational, then n could be the non-integer square root of an integer, whose square is an integer.

S2: An integer multiplied by another integer is an integer.
Manager
Manager
avatar
Joined: 06 Jul 2011
Posts: 213
Location: Accra, Ghana
Followers: 1

Kudos [?]: 35 [0], given: 39

Re: Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an [#permalink] New post 05 Apr 2012, 03:31
Thank you for the explanations. I know have an understanding of the question.
Intern
Intern
avatar
Joined: 07 Feb 2013
Posts: 14
GMAT 1: 650 Q48 V32
GMAT 2: 730 Q49 V41
WE: Engineering (Other)
Followers: 0

Kudos [?]: 13 [0], given: 9

Reviews Badge
Re: Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an [#permalink] New post 20 Jun 2013, 14:07
Stament 1 : n^2=integer
n=+/- sqrt(integer)
=> Sqrt of integer may or may not be integer depending on whether chose integer is perfect square
or not. insufficient

Statement 2: sqrt (n) = integer
=> Squaring both sides
=> n= integer^2 = some other integer (as intg*intg=intg)
= sufficient

Ans B
Senior Manager
Senior Manager
User avatar
Joined: 25 Sep 2012
Posts: 278
Location: India
Concentration: Strategy, Marketing
Schools: Ivey '17
GMAT 1: 660 Q49 V31
GMAT 2: 680 Q48 V34
Followers: 0

Kudos [?]: 87 [0], given: 237

GMAT ToolKit User Reviews Badge
Re: N [#permalink] New post 30 May 2014, 01:27
Bunuel wrote:
vwjetty wrote:
Is n an integer?

(1) n^2 is an integer

(2) n^(1/2) is an integer

Please explain. Thanks.


Is n an integer?

(1) n^2 is an integer --> not sufficient, as if \(n^2=4\) answer is YES, but if \(n^2=3\) answer is NO.

(2) n^(1/2) is an integer --> \(\sqrt{n}=integer\) --> \(n=integer^2=integer\). Sufficient.

Answer: B.


If we take \(\sqrt{3}\) = 1.732050807568877
and square it, we still get 2.999999999999
which is not an integer. That's the reason I marked D :( :roll:

Last edited by b2bt on 30 May 2014, 03:59, edited 1 time in total.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28721
Followers: 4572

Kudos [?]: 47131 [0], given: 7108

Re: N [#permalink] New post 30 May 2014, 02:21
Expert's post
b2bt wrote:
Bunuel wrote:
vwjetty wrote:
Is n an integer?

(1) n^2 is an integer

(2) n^(1/2) is an integer

Please explain. Thanks.


Is n an integer?

(1) n^2 is an integer --> not sufficient, as if \(n^2=4\) answer is YES, but if \(n^2=3\) answer is NO.

(2) n^(1/2) is an integer --> \(\sqrt{n}=integer\) --> \(n=integer^2=integer\). Sufficient.

Answer: B.


If we take \sqrt{3} = 1.732050807568877
and square it, we still get 2.999999999999
which is not an integer. That's the reason I marked D :( :roll:


Writing Mathematical Formulas on the Forum: rules-for-posting-please-read-this-before-posting-133935.html#p1096628 Please read.

\(\sqrt{3}=1.732050807568877293527446341505872366942805253810380628055806...\). It's an irrational number, it goes on forever. Anyway, what's your question?
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

Senior Manager
Senior Manager
User avatar
Joined: 25 Sep 2012
Posts: 278
Location: India
Concentration: Strategy, Marketing
Schools: Ivey '17
GMAT 1: 660 Q49 V31
GMAT 2: 680 Q48 V34
Followers: 0

Kudos [?]: 87 [0], given: 237

GMAT ToolKit User Reviews Badge
Re: N [#permalink] New post 30 May 2014, 03:54
Quote:

Writing Mathematical Formulas on the Forum: rules-for-posting-please-read-this-before-posting-133935.html#p1096628 Please read.

\(\sqrt{3}=1.732050807568877293527446341505872366942805253810380628055806...\). It's an irrational number, it goes on forever. Anyway, what's your question?


How can square of non-integer be an integer?
1.73 is a non- integer and so is its square
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28721
Followers: 4572

Kudos [?]: 47131 [0], given: 7108

Re: N [#permalink] New post 30 May 2014, 04:06
Expert's post
b2bt wrote:
Quote:

Writing Mathematical Formulas on the Forum: rules-for-posting-please-read-this-before-posting-133935.html#p1096628 Please read.

\(\sqrt{3}=1.732050807568877293527446341505872366942805253810380628055806...\). It's an irrational number, it goes on forever. Anyway, what's your question?


How can square of non-integer be an integer?
1.73 is a non- integer and so is its square


The square root of 3 is a number which when squared gives 3.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis ; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) ; 12. 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?
25 extra-hard Quant Tests

GMAT Club Premium Membership - big benefits and savings

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5662
Followers: 319

Kudos [?]: 61 [0], given: 0

Premium Member
Re: Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an [#permalink] New post 21 Jul 2015, 20:29
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

Re: Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an   [#permalink] 21 Jul 2015, 20:29
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic Is n^2 an even integer? avohden 2 01 Nov 2013, 23:56
1 Experts publish their posts in the topic Is n^2 + 2n an integer? (1) n^3 + 3n is an integer. (2) 2n conty911 19 26 Apr 2012, 02:05
2 What is the value of the integer n? (1) N!= (N-1)!*N (2) dimri10 4 06 Jun 2011, 09:39
Experts publish their posts in the topic Is integer N even? 1) N^2=N 2)N=N^3 Statement (1) ALONE is Lombards 3 17 Feb 2011, 13:33
Is positive integer n divisible by 3 ? 1 N^2/36 is an xmagedo 2 19 Jul 2010, 03:49
Display posts from previous: Sort by

Is n an integer? (1) n^2 is an integer (2) n^(1/2) is an

  Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group and phpBB SEO

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®.