different letters of English alphabet are given. Out of these letters, words of letters are formed. How many words are formed when at least one letter is repeated?
Explanation for the correct option:
Step 1. Find the number of words formed:
As we know,
Words which have at least one letter repeated all words possible - words with no letter repeated
Step 2. Find all words possible:
Such word can have alphabets as first letter, 10 letters for second letter and so on.
all words possible
Step 3. Find words with no letter repeated:
Such word can have alphabets as first letter, 9 letters as second letter and so on
words with no letter repeated
Words which have at least one letter repeated
Hence, Option ‘A’ is Correct.