There are 6 possible permutations of 3 letters (ABC). By the fundamental counting principle, if there are m options for the first event and n options for the second, there are m*n total possibilities. The number of permutations of n distinct objects is written as n!. For example, there are 6! possible orders of 6 skiers finishing a competition. The number of permutations of n objects taken r at a time is written as nPr and equals n!/(n-r)!.