Possible number of words taking all letters at a time such that at least one repeating letter is at odd position in each word, is
(A) 9!/2! 2! 2!
(B) 11!/2! 2! 2!
(C) 11!/2! 2! 2! - 9!/2! 2!
(D) 990.7!
Correct option (B) (D)
Explanation:
Since there are 5 even places and 3 pairs of repeated letters therefore at least one of these must be at an odd place
∴ the number of ways = 11!/2! 2! 2!
