In general, repetitions are taken care of by dividing the permutation by the number of objects that are identical! (factorial). 

Example:

                 1.  How many different 5-letter words can be
                     formed from the word   APPLE  ?

                           _{You divide by  2! because the letter  P repeats twice.}

                      _{2.  How many different six-digit numerals can be
                     written using all of the following six digits:
                      4,4,5,5,5,7}

=    6·5 ·4·3·2·1     =    720   =   60           2·1  ·   3·2·1           12

                          _{Two fours repeat and three fives repeat.
                                  2!                               3!}

Schultzkie