A nawab who was a great lover of chess was on his deathbed. He called his three sons and said that his chess set made of diamonds and rubies and worth several million rupees would go to the one who played exactly half as many games of chess as the nawab had days to live — which meant if he lived for say, 20 days, the prince should have played 10 games.
The oldest son refused the challenge saying that he did not know how long his father would live. The nawab said he could condone a mistake of half a day. Still the prince refused. The second son too refused for the same reason. The youngest son accepted the challenge and won.