15
How many mathematicians does it take to change a lightbulb?
A: The answer is trivial and left as an exercise for the reader.
#14
How many folk musicians does it take to change a lightbulb?
5; One to change the lightbulb, and four to write songs about how much better the old bulb was.
#13
How long does it take a performance artist to change a lightbulb?
I don’t know, I left after the first hour and a half.