statistics
posted by Anonymous .
a horse race has 10 entries and one person owns 5 of those horses. assuming that there are no ties, what is the probability that those 5 horses finish 1,2,3, 4th and 5th regardless of the order?

Assume
There are
N=10C5 ways of randomly choosing 5 horses out of 10.
where
N=10!/(5!5!)=25
We assume that
1. order does not count,
2. winning probabilities are equal among horses,
3. results are completely random.
Then the owner has one chance in 252 that his 5 horses are placed 1st to 5th. 
N=10C5=10!/(5!5!)=252

A horse race has 14 entries and one person owns 5 of those horses...

.0009

.0040