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

It is currently 30 Jul 2015, 21:47
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

Which of the following is the lowest positive integer that

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Manager
Manager
avatar
Joined: 18 Oct 2011
Posts: 91
Location: United States
Concentration: Entrepreneurship, Marketing
GMAT Date: 01-30-2013
GPA: 3.3
Followers: 2

Kudos [?]: 40 [1] , given: 0

Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 08:38
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

72% (02:21) correct 28% (01:28) wrong based on 102 sessions
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?

A. 140
B. 210
C. 1400
D. 2100
E. 3500
[Reveal] Spoiler: OA

Last edited by Bunuel on 10 Jan 2013, 15:23, edited 1 time in total.
Renamed the topic and edited the question.
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28780
Followers: 4591

Kudos [?]: 47358 [0], given: 7121

Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 15:27
Expert's post
sambam wrote:
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?

A. 140
B. 210
C. 1400
D. 2100
E. 3500


The first 7 positive multiples of 5 are 5, 10, 15, 20, 25, 30 and 35. The least common multiple of these numbers is 2,100.

Answer: D.

Or, a shortcut approach:
Discard 140, 1,400 and 3,500 because they are not divisible by 3.
Discard 210 because it's not divisible by 4.
Only option D remains.
_________________

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

Intern
Intern
avatar
Joined: 18 Nov 2011
Posts: 37
Concentration: Strategy, Marketing
GMAT Date: 06-18-2013
GPA: 3.98
Followers: 0

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

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 16:58
Bunuel wrote:
sambam wrote:
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?

A. 140
B. 210
C. 1400
D. 2100
E. 3500


The first 7 positive multiples of 5 are 5, 10, 15, 20, 25, 30 and 35. The least common multiple of these numbers is 2,100.

Answer: D.

Or:
Discard 140, 1,400 and 3,500 because they are not divisible by 3.
Discard 210 because it's not divisible by 4.
Only option D remains.



Why are we looking at divisibility by 3 and 4?
Intern
Intern
avatar
Joined: 28 Nov 2012
Posts: 48
Followers: 0

Kudos [?]: 6 [0], given: 3

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 17:33
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?

A. 140
B. 210
C. 1400
D. 2100
E. 3500

Take 5,10,15,20,25,30, and 35

You can eliminate A and B right off the bat because 25 doesn't go into 140 or 210. I found it easier to look take a two of the multiples and test their divisibility among the choices. If one doesn't work its wrong so 30 and 35.

C) Wrong not divisible by 30
D) Yes for both check 15 that's the only other obscure multiple
E) Not divisible by 30
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28780
Followers: 4591

Kudos [?]: 47358 [0], given: 7121

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 17:53
Expert's post
hitman5532 wrote:
Bunuel wrote:
sambam wrote:
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?

A. 140
B. 210
C. 1400
D. 2100
E. 3500


The first 7 positive multiples of 5 are 5, 10, 15, 20, 25, 30 and 35. The least common multiple of these numbers is 2,100.

Answer: D.

Or:
Discard 140, 1,400 and 3,500 because they are not divisible by 3.
Discard 210 because it's not divisible by 4.
Only option D remains.



Why are we looking at divisibility by 3 and 4?


The least common multiple of 5, 10, 15, 20, 25, 30 and 35 must be a multiple of 3 since 15 is a multiple of 3 and it must a multiple of 4 since 20 is a multiple of 4.

Hope it's clear.
_________________

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

Intern
Intern
avatar
Joined: 18 Nov 2011
Posts: 37
Concentration: Strategy, Marketing
GMAT Date: 06-18-2013
GPA: 3.98
Followers: 0

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

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 18:38
I knew I was missing something very simple. Thank you
Manager
Manager
User avatar
Joined: 04 Oct 2011
Posts: 224
Location: India
Concentration: Entrepreneurship, International Business
GMAT 1: 440 Q33 V13
GMAT 2: 0 Q0 V0
GPA: 3
Followers: 0

Kudos [?]: 35 [0], given: 44

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jan 2013, 19:25
first 7 positive multiples of 5 are 5, 10, 15, 20, 25, 30 and 35.

5 = 1* 5
10 = 2 * 5
15 = 3 * 5
20 = 4 * 5 = \(2^2 * 5\)
25 = 5 * 5 = \(5 ^ 5\)
30 = 6 * 5= \(2*3*5\)
35 = 7* 5

So, LCM would be 1 * \(2^2\) * 3 * \(5^5\) * 7 = 2100

actually i made mistake while computing first after going through Bunuel soln i got above one :-D
_________________

GMAT - Practice, Patience, Persistence
Kudos if u like :)

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 5692
Followers: 322

Kudos [?]: 62 [0], given: 0

Premium Member
Re: Which of the following is the lowest positive integer that [#permalink] New post 27 Oct 2014, 06:58
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

Director
Director
User avatar
Joined: 17 Apr 2013
Posts: 626
Concentration: Entrepreneurship, Leadership
Schools: HBS '16
GMAT 1: 710 Q50 V36
GMAT 2: 750 Q51 V41
GPA: 3.3
Followers: 14

Kudos [?]: 124 [0], given: 278

CAT Tests
Fantastic NP : Which of the following is the lowest positive integer t [#permalink] New post 10 Jul 2015, 01:10
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?
140
210
1400
2100
3500
_________________

Like my post Send me a Kudos :) It is a Good manner.
My Debrief: how-to-score-750-and-750-i-moved-from-710-to-189016.html

Director
Director
User avatar
Joined: 17 Apr 2013
Posts: 626
Concentration: Entrepreneurship, Leadership
Schools: HBS '16
GMAT 1: 710 Q50 V36
GMAT 2: 750 Q51 V41
GPA: 3.3
Followers: 14

Kudos [?]: 124 [0], given: 278

CAT Tests
Re: Fantastic NP : Which of the following is the lowest positive integer t [#permalink] New post 10 Jul 2015, 01:11
This is quite tough bunuel your input needed.
_________________

Like my post Send me a Kudos :) It is a Good manner.
My Debrief: how-to-score-750-and-750-i-moved-from-710-to-189016.html

Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 28780
Followers: 4591

Kudos [?]: 47358 [0], given: 7121

Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jul 2015, 01:14
Expert's post
honchos wrote:
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?
140
210
1400
2100
3500


Merging topics.

Please search before posting and name topics properly. Also, please put A, B, C, D, and E in front of the options. Thank you.
_________________

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

Math Forum Moderator
avatar
Joined: 20 Mar 2014
Posts: 531
Concentration: Finance, Strategy
GMAT 1: 650 Q49 V30
GMAT 2: 690 Q49 V34
GPA: 3.7
WE: Engineering (Aerospace and Defense)
Followers: 7

Kudos [?]: 158 [0], given: 88

GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: Which of the following is the lowest positive integer that [#permalink] New post 10 Jul 2015, 04:02
honchos wrote:
Which of the following is the lowest positive integer that is divisible by the first 7 positive integer multiples of 5?
140
210
1400
2100
3500


One way to look at it this :

1st 7 multiples of 5:
5 =1*5
10=2*5
15=3*5
20=4*5=2^2*5
25=5^2
30=2*3*5
35=5*7

Always try to break down the numbers into their corresponding prime factors.

For LCM (least common multiple) take the highest powers of 2,3,5,7 which gives us : 2^2 *3*5^2*7 = 2100. Hence D is the correct answer.
_________________

Thursday with Ron updated list as of July 1st, 2015: http://gmatclub.com/forum/consolidated-thursday-with-ron-list-for-all-the-sections-201006.html#p1544515
Rules for Posting in Quant Forums: http://gmatclub.com/forum/rules-for-posting-please-read-this-before-posting-133935.html
Writing Mathematical Formulae in your posts: http://gmatclub.com/forum/rules-for-posting-please-read-this-before-posting-133935.html#p1096628
GMATCLUB Math Book: http://gmatclub.com/forum/gmat-math-book-87417.html

Re: Which of the following is the lowest positive integer that   [#permalink] 10 Jul 2015, 04:02
    Similar topics Author Replies Last post
Similar
Topics:
Fantastic NP : Which of the following is the lowest positive integer t honchos 0 10 Jul 2015, 01:11
5 Experts publish their posts in the topic What is the lowest positive integer that is divisible by each of the goodyear2013 2 11 Oct 2014, 12:04
8 Experts publish their posts in the topic If a and b are positive integers, which of the following goodyear2013 4 30 Jun 2014, 13:36
18 Experts publish their posts in the topic What is the lowest positive integer that is divisible by Bunuel 14 11 Sep 2012, 03:43
Experts publish their posts in the topic What is the lowest positive integer that is divisible by eac Bunuel 1 06 May 2012, 05:54
Display posts from previous: Sort by

Which of the following is the lowest positive integer that

  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®.