Comedy: A Prof and Akpos played a game

A Prof and Akpos was
seating next to each other in a
long flight.
Prof said to Akpos: lets play a
game, I will ask you a question
and if you didn't get the
answer, you will pay me $50,
and if u ask me a question and I
don't get the answer, I will pay
you $5000.
The Prof started: What is the
distance from the earth to the
moon?
Akpos doesn't say a word, he
reaches his pocket and pulls
out a $50 and gives it to him.
Now it's Akpos turn to ask, He
said: What goes up the hill
with 3 legs and comes down
with 5 legs?
The Prof thought for a long
time,searches the net, and
asked all his smart friends but
couldn't get the answer.
He reached his pocket, pulled out
a $5000 and gave it to Akpos.
The Prof got mad and asked
Akpos:
Well, what the hell goes up the
hill with 3 legs and comes down
with 5 legs?.
Akpos just dipped his hand into
his pocket and gave Prof $50
and said: I don't know also.