My Math Forum  

Go Back   My Math Forum > High School Math Forum > Algebra

Algebra Pre-Algebra and Basic Algebra Math Forum

Thanks Tree1Thanks
  • 1 Post By skipjack
LinkBack Thread Tools Display Modes
July 2nd, 2017, 07:57 PM   #1
Senior Member
Joined: Jul 2011

Posts: 405
Thanks: 16

counting problem

If $n$ persons are sitting around a table $(n\geq 4)$, then the number of arrangements in which all shall not have same neighbours is

Last edited by skipjack; July 2nd, 2017 at 10:37 PM.
panky is offline  
July 2nd, 2017, 11:00 PM   #2
Global Moderator
Joined: Dec 2006

Posts: 20,978
Thanks: 2229

If $n$ is 5 and the original arrangement is denoted by ABCDE, are the new arrangements ACEBD and CEBDA counted as just one rearrangement?

In a new arrangement, is it okay that just one neighbour is different, rather than both?
Thanks from panky
skipjack is offline  
July 3rd, 2017, 07:49 AM   #3
Math Team
Joined: Jul 2013
From: काठमाडौं, नेपाल

Posts: 901
Thanks: 61

Math Focus: सामान्य गणित
Does it mean "everyone has new neighbors" or "at least one(two) has different neighbor"?

Last edited by skipjack; July 3rd, 2017 at 08:21 AM.
MATHEMATICIAN is offline  
July 13th, 2017, 07:16 PM   #4
Senior Member
Joined: Jul 2011

Posts: 405
Thanks: 16

To moderator ACEBD and CEBDA counted as 1, Thanks
panky is offline  
July 25th, 2017, 05:28 AM   #5
Math Team
Joined: Jan 2015
From: Alabama

Posts: 3,264
Thanks: 902

That doesn't answer the question. Do you want the number of orders in which some of the people do not have the same neighbor, or in which none of the people have the same neighbor?
Country Boy is offline  

  My Math Forum > High School Math Forum > Algebra

counting, problem

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
counting problem nwicole Number Theory 4 October 24th, 2014 10:46 AM
Counting problem superconduct Algebra 2 January 7th, 2014 10:01 AM
Counting problem zelmac Algebra 0 February 14th, 2013 05:29 AM
Counting Problem Jakarta Number Theory 6 June 7th, 2012 04:05 AM
Counting Problem julian21 Applied Math 0 April 27th, 2010 09:48 AM

Copyright © 2019 My Math Forum. All rights reserved.