Factorial

In my ASVAB prep course, I place a  great deal of emphasis on the 2 math sections of the ASVAB: Arithmetic Reasoning and Mathematics Knowledge.  The topic of factorials is part of the review I present for Mathematics Knowledge.  When I tutor for the ASVAB, in working to help improve the ASVAB math scores of my students, I make sure to include the topic of factorials.  I remind my students that factorials are not difficult.  Once you know how to solve factorial, it is simple.  Do you know how to solve factorials?  What do you think the answer is?  The answer and explanation will be presented tomorrow.