SOLUTION: How many words can be written using all the letters of the word "IRRATIONAL"?

Count the number of letters, in total :  10.


Count the multiplicities or repeating letters :  2  for  " I ";

                                                 2  for  " R ";

                                                 2  for  " A ".


Write the formula and calculate


    The number of all possible distinguishable arrangements =  =  = 453600.    ANSWER