permutation question example

[Dentalicous1234]

---

Members do not see this ad.

how many arrangements can six people be seated round a circular table?

solutions say it's a circular permutation. (n-1)! = 5! = 120
how is that a permutation? (n-1)! ? that's not even the permuatation formula?

you're not selecting for a number out of them so i don't understand why they would us to use permutations. I just am lost, pleasseee help this stuff totally worries me and the more I study it seems like the more lost I get.

help please!

 

[predentlsu1]

It is rather complicated to try to think about but that is the correct formula. Anytime you have a circular object and the clockwise or anticlockwise orders are different then the total number of arrangements are given by (n-1)!
Clockwise: Jon,Jane,Joe,Sally,Bob,Mike,Tom
Anticlockwise: Tom,Mike,Bob,Sally,Joe,Jane,Jon

Anytime you have a circular object and the clockwise or anticlockwise orders are the same then the total number of arrangements are given by (n-1)!/2!
Clockwise: Blue,Red,Green,Green,Red,Blue
Anticlockwise: Blue,Red,Green,Green,Red,Blue

I just know that those are the formulas for those problems I don't really try to understand why lol.

 

[z3u2]

http://mathworld.wolfram.com/CircularPermutation.html

 

[Dentalicous1234]

okay wow thank you!!!!! this totally helps! Another formula to memorize...

at least it's easier than the probability and combinations ones in topscore. I hope I get a circular permutation question now, it's not as intimidating anymore hehe 😎


anyways THANKS again!