Big Factorial Division

51 is equal to 17 times 3. 17 and 3 are factors of 50! as 1 x 2 x 3 x.....x 17 x..........x 49 x 50, so it is divisible by 51. Therefore, the remainder is 0.

A corollary from the famous Wilson's Theorem :

For every composite number $n\neq 4$ , $(n-1)! \equiv 0$ $(mod$ $n)$ .

So, $\boxed{0}$ is the answer.

50! / 51 = 1x2x3x...17x.....50/51 = 1x2x3x...17x...50/3x17 = 1x2x4x....15x18x...50, No remainder other than zero

50!/51=((1)(2)(3)....(17)(18)....(50))/((3)(17)) ---> the remainder is 0.

$51=17 \times 3$ and $17,3$ are factors of $50!$ so the remainder is $\boxed{\large{0}}$