I work 250 days / year
my average off sick is 5 days /year (mean Imay be off sick 5 days/year)
if I am off sick 2 days within 13 weeks, I willget a warning
what's the probability of having a warning?

any help will be appreciated

Too many variables.

How healthy are you.
Do you take daily vitamins.
Will you work, even though you may not feel 100%.
How busy is the person in charge of issuing the warning.

There is no real way to predict, why would you ask such a question?

You just said you will get a warning if you're off sick 2 days within 13 weeks. So if you're off sick 2 days within 13 weeks I would say 100% probability... if I did my math correctly. Unless they really don't enforce their rules there.

It is a 100 percent chance, there are only four 13 week periods within the year. So without getting a warning you may only have four days missed total. So if you have 5 days missing, you will have to do 2 within a 13 week perid