How to use Wilson theorem in 17!/31 to find remainder ...???kindly help!!!

answer is 5<br>

By extending Wilson’s theorem, we can see that when a prime number ‘p’ is divided by p, (p – 1)! / p will result in a remainder of (p-1). Now 17!/31 should be transformed to wilson format for that ill write it as 17 X 16! ill multiply numerator and denom by 17 so it becomes (p-1)!/p format.Now 17 X17 X16! / 17 X31 16!/17 is 16 so the eqn now becomes 17 X 17 X 17 / 31 which yields a rem of 5

Thanku so much

But in last ...please if you can elaborate more ...how it's 5 coz 17^3/31 then remainder should be 3 right???