In Washington, D.C.
or
Because it would fall over if it lifted the other one.
or
It waves.
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Three. One to climb the ladder while the second kicks the ladder out from under her. And the third to say, "I knew that was too high for you dear."
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Two. One to take notes while the other screws it into the faucet.
or
Aye, Aye, Arr and the Seven C's
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None. There never was any light bulb.
Notes: Probably the only really good light bulb joke of 1984.
or