The number of ways can the letters be rearranged is given by the formula :
[tex]N=\frac{n!}{a!b!c!\ldots}[/tex]where N is the number of ways
n is the number of letters
a, b and c are the number of duplicate letters
From the problem, KINDEST has 7 letters and it has NO duplicate letters so a, b and c are all equal to 1.
Using the formula above :
[tex]N=\frac{7!}{1!}=7![/tex]The answer is B. 7!
