TRICK QUESTION. THEY CAN'T CHANGE ANYTHING.
Two. One to identify that the lightbulb has indeed burned out, and one to call the maintenence man to change the lightbulb.
CHANGE!
None, they will keep worshipping in dark.
Tires need changing too you know!
TRICK QUESTION. THEY CAN'T CHANGE ANYTHING**
Trick question. Idiots can't screw in lightbulbs regardless of help from other idiots.