One bullet, 100 prisoners: Can you crack this brain-teaser?

Signaling only has one “L” in American English.

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The overall quality of content on BB has been in decline as of late, unfortunately.

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… we don’t know what the “point” is until they tell us the “answer,” which will presumably illustrate which detail was the important one, what additional assumptions they didn’t tell us about, and what moral instruction we’re meant to infer from the whole story :confused:

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I’ve always loved the 100 prisoners/boxes puzzle because it’s such a ridiculous mathematical workthrough to get to a fairly elegant practical solution; it’s easy to imagine that somebody was just playing with a fun permutation/probability proof and decided to make up a little story about it.

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I think you’re reading the rules wrong. They are not absolutely risk adverse: they will choose not to act only if acting is guaranteed to get them shot. That is, if the guard announces that a prisoner will be chosen at random to be shot upon any escape attempt, every prisoner will absolutely attempt that 1% risk and run for it.

So the more interesting and rigorously constructed version of this puzzle gives the prisoners perfect knowledge and the full ability to collaborate. If they can collaborate, they can plan to run at the same time, and will accept the < 100% risk. The nature of collaboration is definitely unclear in this statement.

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The collaboration would make it tricky indeed. To counter it, the prisoners could be made to stand far enough apart that whispering isn’t feasible. Then you could do something like telling the prisoners that you’re assigning them all a number from 1-100, and tell them that in an escape attempt the prisoner with the lowest number would be shot. Then hand out 100 slips of paper with the number 1. (This isn’t a thoroughly thought-through solution, obviously, but the answer has to have some sort of wrinkle in it somewhere.)

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It’s possible that brainteasers collectively perpetuate the sort of dated stereotypes that aren’t very helpful for a democracy.

So a child raised on this sort of thing first learns to ignore and then to accept, and then to embrace.

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This is almost the solution; you’ve made it a little more complicated than necessary. There’s a way to make a similar solution work even if you allow for perfect communication among the prisoners.

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So, there’s a movie called Human Centipede 3 (Final Sequence) (I have not seen any movies in the trilogy) and, from what I gather, hypothetically, one high-powered round could go through 500 prisoners (in this particular case).

I think I need more details, at the very least just to keep me from infuriating everyone else working on the puzzle. It’s a math problem, isn’t it? blink

It’s something like the guard gives every prisoner a piece of paper with a random number on it from 1-100, and tells them all that if anyone tries to escape, he’ll shoot the person with the lowest number. After all the prisoners look at their numbers, the one with #1 will obviously not attempt to escape and step aside, then #2 would realize they are now the most at risk, and so on, all the way up to #100.

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Ah-- cover them in grease and release them into a high school, and tell the students to catch all 115 prisoners.

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You convince them it’s a magical bullet that has near infinite inertia and will redirect itself after each person it hits?

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Oof. That’s even less of a brainteaser, but it serves the same purpose. Let’s make up fun scenarios where we can fantasize about killing enemies of the State, as is right and good. :rage:

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Force the prisoners to dig a moat around the field, then fill the moat with alligators.

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That’s a guaranteed fail. Think of it from a prisoner’s perspective: you’re told that if anyone attempted to escape and you’d be shot for it (which all the prisoners now believe because they all hold #1). You could safely assume that Mr./Ms. #99 (who you assume exists, unless you suspect the numbers have been rigged) is going to decide to make a break for it because they aren’t at immediate risk. At which point, you realize that you might as well make a break for it and hope the guard is a crappy shot. And once one prisoner bolts, any who had decided to stick it out would also bolt, because they believe they are about to be shot at.

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My solution would be the following: Strip the shirt that identifies you as the guard. Then pretend to run away while hiding the gun. As soon, as you are some distance away, shoot into the ground and go down, faking to be shoot. Stay on the ground and take a nap. All the prisoners will think, there is a sniper somewhere and will stay.

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well the guard only has one bullet. Once that’s gone, he’s done his duty.

The logic of deterrence requires that humans put aside their moral scruples in order to make fear credible. If a human lacks the capacity to do that, he might as well be replaced by a more logical device.

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… sounds like maybe it should be the guard trying to escape :thinking:

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just to add to the confusion, is this even a complete sentence? i mean, one round what? one round… proboscis? a proboscis of any shape seems a pretty odd thing for a gun have. :thinking:

:musical_note: :musical_note:

Mirrors on the ceiling
The pink champagne on ice
“We are all just prisoners here, of our own device”

although… not many ceilings in a field i suppose.

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Give all the prisoners the number “1” with the same criteria, and tell them you’ll shoot the first person who divulges their number.

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THIS.
This makes a huge difference.

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