Question

A pistol is loaded with one bullet and five blanks and then the cylinder is spun and waited until it stops. A convict is sentenced to Russian Roulette. If he shoots and there is no bullet, he is free. If he doesn't shoot, he spins the gun again and is forced to shoot. What should he do?

Answer 1

@hartnn want to try old times?

Answer 2

he has good odds that he will live, and if he's in a society that enforces law by forcing convicts to play russian roulette...hed probably be better off dead than going to their prison. its a win win for him

Answer 3

So you vote to shoot?

Answer 4

yes

Answer 5

wait a minute what is your question...either way he has to shoot.

Answer 6

so the question is, does spinning increases or decreases the probability of survival of the convict.

Answer 7

well, without spinning , his survival probability is 5/6

Answer 8

hmm..actually, no

Answer 9

why not ?

if he spins, his survival probability decreases, so he shoule not let the person spin...

Answer 10

So there's 6 chambers with one bullet. He randomizes it by spinning it and then has a choice to either pull the trigger, or spin it again and then he must pull the trigger.
Am I reading that correctly?

Answer 11

yes mira

Answer 12

well should his chances be the same either way?
and if can only prolong pulling the trigger once, then why shouldn't he just pull it the first time?

Answer 13

yes, i was thinking both have same chance = 5/6
but since such question is asked, i figured there must be some twist :P

Answer 14

or is he playing with other convicts?

Answer 15

ahh you've learned well, @hartnn

Answer 16

true agreed hartnn

Answer 17

i agree haha im just trying to figure out what that twist could be. there must be one

Answer 18

yes, there is.

Answer 19

If you've ever been Russian Rouletted, then the twist would be obvious, though

Answer 20

or probably dead by now :P

Answer 21

i might have found a similar example online..

Answer 22

i hope not

Answer 23

ah but the online example already assumes the trigger was pulled once

Answer 24

If you want a hint, then:

1) If the first shot is empty, the second is empty
2) If the first shot is not empty, the second is empty

Answer 25

i am thinking....
say the bullet was in hole 3, and hole 5 was shot in first try.

then the probability of getting bullet in hole 3 again is very less....the probability of getting bullet in other holes increases....
so he should not allow spinning...

Answer 26

ok so what i think this problem is getting at is that every time you spin the chamber it resets the probability of firing the bullet to a 5/6 chance before its fired at all there is a 5/6 chance after its fired once without going off the chance is reduced to a 4/5 probability to go off and it keeps going down by one each time you pull the trigger until its a 1/2 or fifty fifty percent chance

Answer 27

however if you got down to the 1/2 chance and then decided to spin it before shooting it ups your odds back to 5/6

Answer 28

im just confused on the wording of the problem because the odds really do seem to be the same either way

Answer 29

should I reveal the trick?

Answer 30

was that the exact wording of the problem?

Answer 31

yes

Answer 32

and go for it :-]

Answer 33

the first and second shot are actually empty no matter what you do. it's less mathematical than it seems.since they wait for the cylinder to stop spinning, the bullet is somewhere at the bottom

Answer 34

lol gravity! :P

Answer 35

ohhhhhhhhh :O
haha good ol phyiscs

Answer 36

then he should always shoot first then right?

Answer 37

with the logic he provided, it doesn't matter :P
he always gets saved!

Answer 38

It does matter, to me everything matterzz! :P