Three: One to screw it in, and two to talk about how much better it is than with a man.
or
Just one, but he'll also want to do something about your nose.
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With Tyrannosaurus checks.
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Nothing, peanuts don't talk.
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One. No, two. No... How many do we have on the truck?
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Seven. One to change it and the other six to sing about how good the old one was.
or
Time is fun when you're having flies
or
A marsbar!
or
None. There never was any light bulb.
Notes: Probably the only really good light bulb joke of 1984.
or
The chicken wasn't around yet.
or