@RailedRobin:
Thank you. But I thought it was simpler.
So I have to add a lot of events, and in my tutorial, there are already too many.
I tried with a formula like this, and a little bit I got there.
Al_value_experiment.jpg
It would be enough to find the sign to replace the plus sign to explain to the computer that it must randomly set the values from 11 to 16, and then sometimes set it to 31! (skipping the values from 0 to 10, and from 17 to 30)
But that plus sign does not recognize it as an interval separation, but as a sum!