One day at school a teacher said, "Class I'm going to give
you a question every Friday. If you answer it correctly,
then you do not have to come to school on the following
Monday."

The first Friday arrived and the teacher asked, "How many
stars are in the sky?"

No one was able to answer.

The next Friday the teacher asked, "How many fish are in the
sea?"

Again, no one was able to answer.

Then one student had an idea. He got two big bouncy balls
and painted them black. On Friday, before she asked the
question, he threw the balls in one of the aisles. The
teacher asked, "Who's the guy with the big black balls?"

The kid yelled, "Bill Cosby! See ya next Tuesday!"