Question 48

Ten different letters are given. Words with five letters are formed from these given letters. The number of words which have at least one letter repeated is

Solution

Number of words in which all the 5 letters are repeated = $$10^5=100000$$

Number of words in which no letter is repeated = $$P^{10}_5=30240$$

=> Number of words which have at least one letter repeated = $$100000-30240=69760$$

=> Ans - (A)

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