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

It is currently 24 Oct 2014, 18:51

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

What is the quick litmus test to see whether an integer is

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
User avatar
Joined: 21 Jan 2007
Posts: 2769
Location: New York City
Followers: 8

Kudos [?]: 257 [0], given: 4

What is the quick litmus test to see whether an integer is [#permalink] New post 26 Oct 2007, 08:48
What is the quick litmus test to see whether an integer is divisible by 7
VP
VP
avatar
Joined: 10 Jun 2007
Posts: 1467
Followers: 6

Kudos [?]: 108 [0], given: 0

Re: Divisibility Rule [#permalink] New post 26 Oct 2007, 11:37
bmwhype2 wrote:
What is the quick litmus test to see whether an integer is divisible by 7


No rules that I know of.
Prime factorization? Or just divide by 7, shouldn't take that long...
CEO
CEO
User avatar
Joined: 21 Jan 2007
Posts: 2769
Location: New York City
Followers: 8

Kudos [?]: 257 [0], given: 4

Re: Divisibility Rule [#permalink] New post 26 Oct 2007, 11:39
bkk145 wrote:
bmwhype2 wrote:
What is the quick litmus test to see whether an integer is divisible by 7


No rules that I know of.
Prime factorization? Or just divide by 7, shouldn't take that long...


I came across several questions that asked this concept.


is 342234234123 divisible by 7? lol
VP
VP
User avatar
Joined: 08 Jun 2005
Posts: 1156
Followers: 6

Kudos [?]: 118 [0], given: 0

Re: Divisibility Rule [#permalink] New post 26 Oct 2007, 11:50
bmwhype2 wrote:
bkk145 wrote:
bmwhype2 wrote:
What is the quick litmus test to see whether an integer is divisible by 7


No rules that I know of.
Prime factorization? Or just divide by 7, shouldn't take that long...


I came across several questions that asked this concept.


is 342,234,234,123 divisible by 7? lol


I use approximation

since ---> 7*4 = 28 ---> then:

342,234,234,123 - 280,000,000,000 = 62,234,234,123

7*8 = 56

62,234,234,123 - 56,000,000,000 = 6,234,234,123

6,234,234,123 - 5,600,000,000 = 634,234,123

634,234,123 - 560,000,000 = 74,234,123

7*10 = 70

74,234,123 - 70,000,000 = 4,234,123

7*6 = 42

4,234,123 - 4,200,000 = 34,123

34,123 - 28,000 = 6,123

6,123 - 5,600 = 523

523 - 490 = 33

this number dosen't divide by 7 !

:)
VP
VP
avatar
Joined: 10 Jun 2007
Posts: 1467
Followers: 6

Kudos [?]: 108 [0], given: 0

Re: Divisibility Rule [#permalink] New post 26 Oct 2007, 12:19
bmwhype2 wrote:
bkk145 wrote:
bmwhype2 wrote:
What is the quick litmus test to see whether an integer is divisible by 7


No rules that I know of.
Prime factorization? Or just divide by 7, shouldn't take that long...


I came across several questions that asked this concept.


is 342234234123 divisible by 7? lol


I would just divide that number by 7. Should take about 20 seconds max.
Do you have an actual problem?
Re: Divisibility Rule   [#permalink] 26 Oct 2007, 12:19
    Similar topics Author Replies Last post
Similar
Topics:
1 Simple and quick divisibility test for 7 Vishwa25 4 05 Feb 2013, 23:27
1 Experts publish their posts in the topic The Coast Guard is conducting tests to see whether pigeons vanidhar 5 21 Oct 2010, 21:53
The Coast Guard is conducting tests to see whether pigeons xmagedo 4 17 Jun 2010, 22:46
5 Experts publish their posts in the topic The Coast guard is conducting tests to see whether pigeons rakesh_chi 13 25 Oct 2007, 20:50
Quick Pronoun Test willget800 1 12 Jun 2006, 17:58
Display posts from previous: Sort by

What is the quick litmus test to see whether an integer is

  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®.