gmat preparation courses

It is currently Mon Jan 22, 2018 2:29 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: GMAT Counting Methods
PostPosted: Sun Jan 29, 2012 7:43 pm 
Offline

Joined: Sun May 30, 2010 3:15 am
Posts: 424
If each digit in the set A = {1, 2, 3, 4, 5} is used exactly once, in how many ways can the 5 digits be arranged?
A. 6
B. 24
C. 72
D. 96
E. 120

(E) There are 5! = 120 possible arrangements of the five digits with no restrictions. Every time an item is selected, it is reduced from the pool. (5)(4)(3)(2)(1) = 120
----------
Remember the rule of combination.


Top
 Profile  
 
 Post subject: Re: t.1, qt. 17: combinatorics, permutations.
PostPosted: Sun Jan 29, 2012 7:54 pm 
Offline

Joined: Sun May 30, 2010 2:23 am
Posts: 498
Quote:
Remember the rule of combination.
In this question we deal with permutations.

A combination would be some subset of a given set (order does NOT matter). For example, selecting three numbers out of five.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


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:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group