The total number of different arrangements of 7 letters that are possible if the first letter will be w or k is:
617,831,552
The number of different arrangements of 7 letters can be formed if the first letter must be w or k such that the repetition of the letters are allowed are:
2×26×26×26×26×26×26
( Since, at the first place any of the 2 letter out of w or k could come up.
and from the second to seventh place any of the 26 letters of the English alphabet may come up )
Hence, total number of arrangements = 617,831,552
