The letters of the word “PATNA” are arranged in all possible ways as in a dictionary, then the rank of the word “PATNA” is

No. of words start with A, No. of words start with N, =4!2!=12 No. of words start with PAA 2!=2 No. of words start with PAN, = 2! =2Total = 40Next words are PATAN, then PATNA so the 42nd word.