Three. One to change it while the other two argue about how old the old one is.
Because you have to change them.
Three. One to pay a Mexican to do it, two to deport him afterwards.
None a burned out bulb can't catch a waiter's eye.
There's really no sure way to know.
Kurt Fossil
His old one wouldn't let him swab her poop deck.
Seven. One to install the bulb and six to figure out what to do with the old one for the next 10,000 years