6: 2 to screw in the bulb and 4 to testify that it was lit from the moment they began screwing.
or
2 years old.
Cow: "Mooooove over"
Sheep: "Naaaaaaa."
or
Nearly unanswerable, since the one who tries to change it usually drops it, and the others call for a planning session.
or
He was tired of working for peanuts.
or
Because he saw the salad dressing!
or