Register    Login    Search    Rss Feeds

Forums Home » Ask An Instructor » GMAT Math » GMAT Prep Math


 Page 1 of 1 [ 2 posts ] 



  Print view Print view Previous topic Previous topic | Next topic Next topic
 

Number properties

Author Message
viveksunder.vs
 Post subject: Number properties
 Post Posted: Sat Mar 21, 2009 10:46 pm 
Offline


Posts: 7
For every positive even integer n, the function h(n) is defined to be the product of all even integers from 2 to n, inclusive. If P is the smallest prime factor of h(100)+1, then p is?

a)between 2 and 10
b)between 10 and 20
c)between 20 and 30
d)between 30 and 40
e)greater than 40

How do you find the prime factors for such problems?
Top 
RonPurewal
 Post subject: Re: Number properties
 Post Posted: Wed Mar 25, 2009 3:25 pm 
Offline
ManhattanGMAT Staff


Posts: 7146
this is quite possibly the most frequently posted problem on this whole forum.

here are a couple of resources:
post14808.html
post5477.html

--

you don't FIND the prime factors in a problem like this; the whole point of the problem is that there AREN'T any prime factors within a certain range (i.e., 50 or below).

in fact, finding prime factors of large numbers is so hard that it forms the basis for essentially all modern cryptography. so yeah, you don't want to try to find the prime factors in this problem.
Top 
Display posts from previous:  Sort by  
 
 Page 1 of 1 [ 2 posts ] 





Who is online

Users browsing this forum: No registered users and 0 guests

 
 

 
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to: