None, because they can't change anything.
How many do you want?
I don't know, I just set the bulb down somewhere, now I can't find it. Where the hell did the bulb go?
A: Executive Producers don't screw in a light bulb they screw in a hot tub.
A: A fish!
Two. One to identify that the lightbulb has indeed burned out, and one to call the maintenence man to change the lightbulb.
None, that's what students are for.
