Four With Ties
There are 4! = 24 ways to rank four objects. However, a friend told me that if ties
are allowed, the number increases to 75.
I
attempted to list all the possibilities by first listing the 24 orderings of
four objects, then using brackets to group ties involving two players, then
group ties involving three players, and finally the single case in which all
four objects are tied. But something has gone wrong; my list includes just 69
possibilities, not 75.
What
happened? Did I miss something, or was my friend mistaken?
This brainteaser was
written by Derrick Niederman.