Question 1089015
.
10*9*8*7 = 5040.


See

<A HREF=http://www.math.wsu.edu/faculty/dzhang/201-spring2013/201lecturenotes-spring13/Wed4-10written.pdf>http://www.math.wsu.edu/faculty/dzhang/201-spring2013/201lecturenotes-spring13/Wed4-10written.pdf</A>


http://www.math.wsu.edu/faculty/dzhang/201-spring2013/201lecturenotes-spring13/Wed4-10written.pdf