Why some cases in solutions' result section is invisible/hidden???

Question

I wrote some codes for solutions in python... even I passed thru 4/5 cases , I can't solve the #4 case in several problems(2 problems so far)
To proceed solving #4 case there is no way! It says it is "hidden"
Someone help😀
https://www.sololearn.com/coach/127?ref=app

Answer 1

My code worked fine passing all tests. Most likely, you output a negative number for something like:
20
3
3*10 is 30 so you are expected to output nothing because you only have 20.

Answer 2

Test cases are hidden so that people don't hard code their way out of all the problems.

Answer 3

John Wells hi😊
Is this a bug?
I can't get thru #4 case in 2 problems

Answer 4

AMOGHA. A. K. Hi
I did tried several times , can't pass from #4 case