The word NANAKMATTA has 10 letters in all. The letter ‘A’ occurs 4 times, the letter ‘N’ occurs 2, letter ‘T’ occurs 2 times and the remaining two letters K & M each occur once.
∴ The require number of permutations
= 10! /4!2!2!1!1!
= 10! /4!2!2!
= (10*9*8*7*6*5*4!)/4!2*2
= (10*9*4*7*3*5)
= 37800