Pick a colour - still more.

As an addendum to yesterday's post, I understand that our three card problem is a modern take on a very successful scam run by a French commercial travelling salesman in the late 19th century.  He would go down the local tavern and gather together those drinking there.  He would then produce three cups.  Into one he would put two gold coins, into another two silver coins, and into the third, one gold coin and one silver one.  He would shuffle the cups and invite someone to pick a cup at random and take out one coin from it.  He would then offer to bet anyone interested that the other coin in that cup would be the same colour as the one drawn.  If you followed yesterday's reasoning you will realise that he would on average win the bet two times out of three.  Of course the neat part of his trick was that he was a traveller, and so the next night he would be in a different place in a different tavern with a new different unsuspecting audience.  Apparently he made considerably more from his con than he did from his job!