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

It is currently 26 May 2016, 16:20
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

Counting factors of a number

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Director
Director
User avatar
Joined: 08 Jul 2004
Posts: 598
Followers: 2

Kudos [?]: 157 [0], given: 0

Counting factors of a number [#permalink]

Show Tags

New post 22 Jul 2004, 09:25
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Hi all
How does one count the factors of a given number consdiering 1 and number itself.
Thanks
CIO
CIO
User avatar
Joined: 09 Mar 2003
Posts: 463
Followers: 2

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

 [#permalink]

Show Tags

New post 22 Jul 2004, 12:08
Be extremely systematic. I make couples, starting with one, and counting up. You'll soon cover everything:

60:
1&60
2&30
3&20
4&15
5&12
6&10

By counting up on the low end, you cover everything on the high end as well. In this example, the next factor up from 6 is 10, and that's already there, and so is everything else above 10. This is better than randomly throwing out numbers until you hit them all.

Try it with a couple of examples that have lots of factors, like 24, 72, 36, 105.

Try it also with some variables: Name all the factors of 4p if p is a prime number.
4p:
1&4p
2&2p
4&p

That's it!
Manager
Manager
User avatar
Joined: 07 May 2004
Posts: 183
Location: Ukraine, Russia(part-time)
Followers: 2

Kudos [?]: 12 [0], given: 0

Re: Counting factors of a number [#permalink]

Show Tags

New post 22 Jul 2004, 12:55
saurya_s wrote:
Hi all
How does one count the factors of a given number consdiering 1 and number itself.
Thanks


Dear saurya_s, we(me and gravedigger) are working on a system of automated training which will contain easy and quick formulas for this and other things.
Joined: 31 Dec 1969
Location: India
Concentration: Marketing, General Management
GMAT 1: 710 Q49 V0
GMAT 2: 700 Q V
GMAT 3: 740 Q40 V50
GMAT 4: 700 Q48 V38
GMAT 5: 710 Q45 V41
GMAT 6: 680 Q47 V36
GMAT 7: Q42 V44
GMAT 8: Q42 V44
GMAT 9: 740 Q49 V42
GMAT 10: 740 Q V
GMAT 11: 500 Q47 V33
GPA: 3.3
WE: Sales (Investment Banking)
Followers: 0

Kudos [?]: 146 [0], given: 97169

Combinations [#permalink]

Show Tags

New post 22 Jul 2004, 13:55
I know it is done using combinations and using binomial coefficients. For example for 6 (excluding 1 and 6) ie 2x3 is 2C0+2C1 or something like this but I am not sure exactly. There might be some one of us knowing it. Let's take an example how many salads can one make using- lettuce, cucumber, cabbage. Now salad can be made by selecting one of these at at time or 2 at a time or 3 at a time. So, it is 3C1+3C2+3c3= 2^3-1=7
as 3C0+3C1+3C2+3c3=(1+1)^3. Now 3C0 is one so, the answer is 2^3-1=7
Now can some one extend this for factors of number.
Best
S
Combinations   [#permalink] 22 Jul 2004, 13:55
Display posts from previous: Sort by

Counting factors of a number

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| 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®.