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

It is currently 12 Jul 2014, 05:50

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

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
User avatar
Joined: 09 Oct 2007
Posts: 468
Followers: 1

Kudos [?]: 18 [0], given: 1

GMAT Tests User
counting factors [#permalink] New post 30 May 2008, 10:46
1
This post was
BOOKMARKED
Hi, I remember there was a formula to count factors, but I can't find the notebook where I wrote it it.

If I recall correctly, you had to find all the prime factors, then turn them into base-exponents format, then drop the base, then add 1 to each exponents and then multiply them. Is this correct?

IE: Factors of 200?

200 =
(2)(2)(2)(5)(5), therefore: (2^3)(5^2),
(3+1)(2+1) = (4)(3) = 12

200 has 12 factors total.

Can someone confirm?
Manager
Manager
avatar
Joined: 28 May 2008
Posts: 98
Followers: 2

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

Re: counting factors [#permalink] New post 30 May 2008, 19:48
asdert wrote:
Hi, I remember there was a formula to count factors, but I can't find the notebook where I wrote it it.

If I recall correctly, you had to find all the prime factors, then turn them into base-exponents format, then drop the base, then add 1 to each exponents and then multiply them. Is this correct?

IE: Factors of 200?

200 =
(2)(2)(2)(5)(5), therefore: (2^3)(5^2),
(3+1)(2+1) = (4)(3) = 12

200 has 12 factors total.

Can someone confirm?


Yes that is correct !
Here s the formula
The number of divisors of a given number N(including 1 and the number itself)
where N= (a^m)(b^n)(c^m), where a,b,c are prime numbers ,are
(1+m)(1+n)(1+p)

for eg 70=(2^1)(5^1)(7^1)
Therefore, No of divisors= (1+1)(1+1)(1+1)=8
those would be 1,2,5,7,10,14,35,70

Hope thats clear !


Cheers !
Re: counting factors   [#permalink] 30 May 2008, 19:48
    Similar topics Author Replies Last post
Similar
Topics:
Experts publish their posts in the topic The "factor count" of an integer n greater than 1 is the num avohden 2 22 Oct 2013, 19:22
counting sanjay_gmat 4 03 Apr 2009, 13:25
Counting Shelleb17 6 17 Jan 2009, 04:32
When we're asked to count the # of factors of a certain ggarr 3 08 Apr 2007, 06:34
Counting factors of a number saurya_s 3 22 Jul 2004, 08:25
Display posts from previous: Sort by

counting factors

  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®.