Ten different letters of alphabet are given, words with 5 letters are formed from these given letters. Then, the number of words which have at least one letter repeated is:	Answers.
A) 69760 B) 30240 C) 99748 D) 42386 E) None
Solution:   Number of words which have at least one letter replaced,   = Total number of words - total number of words in which no letter is repeated.   =&gt; 105 – 16P5.   =&gt; 100000 − 30240 = 69760.   69760nswer: Option 69760
<result>A</result>
Ten different letters of alphabet are given, words with 5 letters are formed from these given letters. Then, the number of words which have at least one letter repeated is: