View Full Version : math help please probablity


RING12
08-21-2006, 12:09 PM
:idea: how many arrangment can six people are seated around a circle table?

answer is 120. but i thnk it should be 270.(6!)

cl2137
08-21-2006, 12:12 PM
:idea: how many arrangment can six people are seated around a circle table?

answer is 120. but i thnk it should be 270.(6!)

for a circular table, the formula is (n-1)! So it's 5!

desert
08-21-2006, 12:46 PM
:idea: how many arrangment can six people are seated around a circle table?

answer is 120. but i thnk it should be 270.(6!)


If they were sitting in a row of a table, the answer would have been
N! = 6! =6*5*4*3*2*1 =720

Since those are sitting in a circle table, two people (#1 and #6) are sitting close. So actually there is only 5! case can be possible. The answer will be
N! =5! =6*5*4*3*2*1 = 120

Or you may think (N-1)! = (6-1)! =5!

tissy
08-21-2006, 12:52 PM
Nice !!
If they were sitting in a row of a table, the answer would have been
N! = 6! =6*5*4*3*2*1 =720

Since those are sitting in a circle table, two people (#1 and #6) are sitting close. So actually there is only 5! case can be possible. The answer will be
N! =5! =6*5*4*3*2*1 = 120

Or you may think (N-1)! = (6-1)! =5!