Using all the letters of the word "NOOKIASS", how many words can be formed, which begin with N and end with S? Choose the correct choice from the following options.
A) 550 B) 160 C) 720 D) 620 E) 820
There are five letters in the given word.   Consider 8 blanks ....   The first blank and last blank must be filled with N and S all the remaining three blanks can be filled with the remaining 6 letters in 6! ways.   The number of words = 6! = 720.   Answer: 720
<result>C</result>
Using all the letters of the word "NOOKIASS", how many words can be formed, which begin with N and end with S?