# Russian Roulette Based Puzzle

• Aug 14th 2008, 10:02 AM
Obsidantion
Russian Roulette Based Puzzle
The mafia has kidnapped you and says that if you answer a question of theirs correctly that they will let you go free:

There are 4 guns on a table in front of you and another is being held to your head. Of the 5, one gun has 1 chamber, one has 2 chambers, one has 3, another 4 and the last has 5 chambers.

The person holding the gun to your head says that he chose it at random amongst the other 4 and put a random amount of bullets in it from 1 to the amount of chambers that were available.

The question you have to answer to avoid risking death is: If he pulls the trigger once, what is the chance that you will be shot and die regarding the information you have been presented with?
• Aug 14th 2008, 10:44 AM
Quick
actually I think that you have 50% chance if he picks a gun with more than one round in it and 100% chance if he picks the gun with just the one chamber.

So that would mean the total odds would be: $1\cdot \frac{1}{5} + .5\cdot \frac{4}{5}$

So I say that you have a 3/5 chance of dying, or 60%
• Aug 14th 2008, 12:34 PM
Obsidantion
Quote:

Originally Posted by Quick
actually I think that you have 50% chance if he picks a gun with more than one round in it

Say he picks the gun with 2 rounds/chambers, he'll fill it with either 1 or 2 bullets (not 0) which would lead to one of three outcomes: