All the letters of the word GTWENTY are written in all possible ways with or without meaning and these words are written as in dictionary order. Then the serial number of the word "GTWENTY" is
 

The words starting with E   = 360
The words starting with GE =  60
The words starting with GN = 60
The words starting with GTE = 24
The words starting with GTN = 24
The words starting with GTT = 24
    GTWENTY =  1
          Total = 553