It's not a bulb it's a globe.
Only one, but it take 4 episodes and Krilin died at the end.
One. They simply hold the bulb and wait for the world to revolve around them.
It takes four. One to screw in the bulb, and three others to watch and say, "Really dude, you look huge!"
You hold the lightbulb and every politician screws you!
A. Hell you need 250 just to lobby for the research grant.
Well, first off, it's called a lamp...