How many times can you subtract the number 5 from 25?
Once?
One dark knight, a Witch and a Wizard go into a castle for the night, there is no body in the castle when they go in, and nobody goes in to the castle during the night. The next morning three people come out. How can this be?
The dark knight, the Witch and the Wizard come out. There are three that go in in the first place.