Question 1202902
.


There is another way to solve the problem.



In all, we have  6  letters  A,  B,  C,  D,  E,  and  F,  and 

6! = 6*5*4*3*2*1 = 720   of their possible permutations.


From it,  subtract 5! = 120 permutations,  where letter  C  is first, 
and another  5! = 120 permutations,  where letter  C  is the last.


You get the answer    720 - 120 - 120 =  480 permutations.


<U>ANSWER</U>.  &nbsp;&nbsp;&nbsp;&nbsp;7! - 5! - 5! = 720 - 2*120 = 480 &nbsp;permutations.