Literally dozens.
They don't change it. They just watch it burn out, then follow it around for another 15 years.
One. We are efficient and don't like humour.
A: One. No two. No... How many do we have on the truck
One to over hype the new lightbulb and one to make sure it breaks within a year.
The guy who can carry a cup of coffee in each hand and a dozen donuts.
A chicken egg.