In a race among 10 contestants, how many orders of finish are there, counting possibilities of ties?

For example, in a 4-person race, A and B finishing at the same time, before C and D finish simultaneously, is a different order from C and D finishing together before A and B finishing together, and of course each of the 4! ways of all finishing separately are different orders.

There are 102,247,563 possibilities.

Please see Combination Lock from Wolfram MathWorld or

the Online Encyclopedia of Integer Sequences: A000670.

Posted by Dennis on 2008-01-12 12:41:10