1) Ten different letters of an alphabet are given, words with five letters are formed from these given letters. Then the number of words that have at least one letter repeated is A) 69760 B) 30240 C) 99784 D) None of these Answer: Option AExplanation:The total number of words that can be formed = 105. The number of words in which no letter is repeated = 10P5. So, the number of words in which at least one letter is repeated = 105 - 10P5 = 69760.
