Well, you’ve sneezed again without a ticket. And this time you have done it in the homeland of Lord Shiva where laws are a disaster. It has its peculiar justice system known as rule of 21. Sneezing before sunset without a ticket is a punishable offence there.
The jury is divided, so you will decide your own fate. You’re presented with two urns, each of which contains 21 white balls and 21 black ones. Blindfolded, you must choose an urn at random and then draw a ball from it; a black ball means the police will first beat you like drums and then snuff up your nose and force you to sneeze 21 times, but a white one means you get 21 free tickets.
Tradition gives you the option to distribute the balls however you like between the two urns before you don the blindfold. This is thought to be a formality, as the total proportion of white balls to black does not change.
What should you do?
The jury is divided, so you will decide your own fate. You’re presented with two urns, each of which contains 21 white balls and 21 black ones. Blindfolded, you must choose an urn at random and then draw a ball from it; a black ball means the police will first beat you like drums and then snuff up your nose and force you to sneeze 21 times, but a white one means you get 21 free tickets.
Tradition gives you the option to distribute the balls however you like between the two urns before you don the blindfold. This is thought to be a formality, as the total proportion of white balls to black does not change.
What should you do?
1 comment:
Put one white ball in the first urn and the remaining 83 balls in the second.
If you choose the first urn, you go free. If you choose the second, you have 41 chances out of 83, or nearly 50 percent. Altogether this strategy raises your chance of survival to nearly 75 percent.
Adapted from George Gamow and Marvin Stern, Puzzle-Math, 1958.
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