Thread: Wilson's Theorem

Using Wilson's theorem, find the least positive residue of 8*9*10*11*12*13 modulo 7.

I cant really imply "6!=-1(mod 7)" in this question, how do i use it?

8 mod 7 = 1
9 mod 7 = 2
...
13 mod 7 = 6
8*9*10*11*12*13 mod 7 = 6! mod 7 = -1