Math, asked by Mecrin, 1 year ago

How many words can be formed using letter of UNIVERSITY using
each letter at most once?
i) If each letter must be used,
ii) If some or all the letters may be omitted.


Mecrin: for No.of eight letter words
Mecrin: =10c3*7!
Jahnvi97: 10C8 * 8! = 10!/2
Mecrin: sorry i have written wrong
Jahnvi97: 10c3*7! or 10c7*7! is for seven letter words
Mecrin: NO of =& letter word=10C3*7!
Mecrin: please replay me fast!!!! today itself i want thAT !!
Jahnvi97: i told yu naa you are correct...NO of =& letter word=10C3*7!

Answers

Answered by kvnmurty
62
Letters in the word UNIVERSITY:  E, I,N,R,S,T,U,V,Y

There are 9 distinct letters.   Let us say that each letter is used only once in formation of words of any length.    Let P(m, n) denote the number of permutations of selecting n items from m, ie., m! / (m-n)!

1. Number of 9 letter words:
      If all 9 letters are to be used:    9 !

2.  If words contain  0 to 9 letters:  Sum P(9, n)  with n denoting the number of letters to be present in the word.

         P(9,0) + P(9,1)+ P(9,2) + P(9,3) +.... + P(9,8) + P(9,9)
       (1) + (9) + (9*8)  + (9*8*7) + (9*8*7*6) +.....(9!/3!) + (9! /2! )+ (9!/1!) + 9!
     
please calculated the sum.

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If you are looking for formation of 8 letter words:  P(9,8) = 9!/1! = 9!

kvnmurty: click on thanks button above pls;
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