[Paul2432]

Here is what you should do. Get three playing cards, a queen of spades and two aces. He will deal the three cards face down. You select a card and then he flips up a an ace.

Now make a bet with him. Tell him "I bet you $5 I can find the queen. I am so sure, if I am wrong I will pay you $6." Your friend should jump at this proposition. In fact, you make $1.33 per deal.

Repeat until your friend is broke.

Or you could just do the experiment without the bets. It should be obvious fairly quickly that your friends are wrong.

Paul

Edit: One small caveat. Make sure you randomize which card you pick. For example, if you always picked the first card, your friend would always deal the queen to the first position and you would lose. The best way to do this is to roll a die to pick.