The letters of the word ‘SURITI’ are written in all possible orders, and these words are written out as in a dictionary. Find the rank of the word ‘SURITI’.


Given the word SURITI.

Arranging the permutations of the letters of the word SURITI in a dictionary:


To find: Rank of word SURITI in dictionary.


First comes, words starting with letter I = 5! = 120


words starting from letter R = 5!/2! = 60


words starting from SI = 4! = 24 (4 letters no repetation)


words starting from SR = 4!/2! = 12 (4 letters, one repetation of I)


words starting from ST = 4!/2! = 12 (4 letters, one repetation of I)


words starting from SUI = 3! = 6 (3 letters no repetation)


words starting from SUR; SURIIT = 1


SURITI = 1


Rank of the word SURITI = 120 + 60 + 24 + 12 + 12 + 6 + 1 + 1


= 236


Hence the rank of the word SURITI in arranging the letters of SURITI in a dictionary among its permutations is 236.


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