During my last visit to Las Vegas in the USA, I met a man who was an inveterate gambler. He took out a coin from his pocket and said to me, “Heads I win, tails I loose. I will bet half the money in my pocket”. He tossed the coin, lost and gave me half the money in his pocket. He repeated the bet again and again each time offering half the money in his pocket. The game went on for quite some time. I can't recollect exactly how long the game went on or how many times the coin was tossed, but I do remember that the times he lost was exactly equal to the number of times that he won. What do you think, did he, on the whole, gain or lose?