how many zero is there in right in this question 200!/120!

If you're referring to trailing zeroes....

The top number has 40 + 8 + 1 = 49 trailing zeroes

The bottom number has 24 + 4  = 28 trailing zeroes

So, the final result will have  [49 - 28]  = 21 trailing zeroes.....!!!!

Here is an explanation of how this "works".....

Trailing Zeroes In A Factorial