Question

Ten different letters of an alphabet are given, words with five letters are formed from these given letters. Then the number of words which have at least one letter repeated is

• A. \( 69760 \)
• B. \( 30240 \)
• C. \( 99784 \)
• D. None of these

Hint:

To find the number of words with repeated letters, subtract the number of words without repetition from the total possible number of words.

Answer 1

The Correct Option is C

The total number of words without restriction is \( 10^5 \), and the number of words with no repetition is \( 10 \times 9 \times 8 \times 7 \times 6 \). Subtract the number of words without repetition from the total.
Final Answer: \[ \boxed{99784} \]