There was a boy named Johnny.

One day in school, his teacher announced that every Friday she would ask a question and whoever could answer it wouldn't have to come to school the following Monday.

When Friday arrived, she asked, "How many trees are there in the world?"

No one knew, so everyone had to come back to school on Monday.

The next Friday she asked, "How many blades of grass are on the school lawn?"

No one knew, everyone had to come back to school.

Friday after Friday, the teacher would ask these impossible-to-answer questions, and Johnny was getting very tired of those questions that no human could answer, and of going to school on Monday.

So on Thursday night, when he got home, he spray-painted 2 ping pong balls black.

On Friday, just before the teacher asked Friday's Question, Johnny threw them up on her desk.

She picked them up and asked angrily, "Okay, who's the comedian with the black balls?"