My top funniest joke ever!!!

An American lawyer and a Nigerian are sitting next to each other on a long flight. The lawyer is thinking that Nigerians are so dumb that he can fool them easily..,....,. so the lawyer asks if the naija guy would like to play a fun game. The nigerian is tired and just wants to rest, so he politely declines and tries to catch some sleep. The lawyer persists and says that the game is a lot of fun "I ask u a question and if you don't know the answer, you pay me only 5dollars; you ask me one and if I dont know the answer, I will pay u $500.

As naija no be dull guys naau, this catches the nigerian's attention and to keep d lawyer quiet, he agrees to play the game.
The lawyer asks d 1st question "what's the distance from earth to the moon?
The naija guy doesn't say a word, reaches in his pocket pulls out 5dollars the hands it to the lawyer. Now, it's the omo naija turn. He ask the lawyer, "what goes up a mountain with 3 legs and comes down with four?
The lawyer uses his laptop, searches the internet and even the Library of Congress. He sends emails to all his smart friends he knows, all to no avail. After 1 hour of futile searching, he finally gives up. He wakes the naija guy and hands him $500. The nigerian pockets the $500 and goes right back to sleep.
The lawyer is going crazy not knowing the answer. 
So he wakes the naija guy up the asks, "well, so what goes up a mountain with 3 legs and comes down with four? The nigerian reaches in his pocket, hands the lawyer 5dollars and goes back to sleep.