Ok, I will add another one.
The elevator
A freestyler lives in an appartment, on the 11th floor. When he goes freestyling outside, he takes the elevator to leave the building.
Later that day, when he has finished freestyling, he gets in the elevator. If someone else is in the elevator, or if it has been raining, he directly
goes to the 11th floor. If not, he goes to the 7th floor and walks up the other 4 stairs to get to his appartment.
Why is this the case?
Maybe there is more than one solution, but only one is satisfying.
If you already know it, please don't answer it ;)