Twenty. One to hold the bulb, two to turn the ladder, and seventeen on the guest list.
or
Clerk: "Yes, sir. What size does your alligator wear?"
or
Because it gave him a big wave!
or
Seven. One to install the new bulb and six to figure out what to do with the old one for the next 10,000 years.
or
Because her mom would make her take it back.
or