"He says, “Here’s some good news. The way we do the death
penalty here is that you have a chance to get out of it. Here’s the
deal: Two of the jelly beans on the stump are poisonous—you’ll die
within 30 seconds of eating either one of them. But one of the jelly
beans isn’t poisonous and won’t harm you at all. All three of the jelly
beans are delicious. The situation works like this: You pick one of the
jelly beans and eat it, and if you happen to pick the non-poisonous one,
you’re free to go. Cool?”
“Cool,” you say. He tells you it’s time to choose a jelly bean.
You choose the green one."
Then I think “OK, what’s the trick? Surely you’re 66% f*cked”, so I read some comments (basically, they’re mostly TLDR) and I’m like, “WTF are these people talking about?!”.
Zathras knows (sorry if I’ve already made this joke).
Unfortunately, the problem I can’t get past the fact that I should count on the impartiality and fairness of this man who thinks Wesley deserves the death penalty for accidentally stepping on poorly marked flowers in the one area on the planet that arcane law will be enforced this week.
I’m with @Boundegar (and others). The statistics work. The knowledge of other humans, however, says the statistics are likely wrong in the real life application of this scenario.
Coming from another angle, let’s say it was your plum and some stranger stole it and you could enforce the death penalty in the form of a Monty Hall game. I would hope most of us would “neglect to see” the crime and maybe offer some friendly advice to the stranger about the local dangers of plum theft laws hereabouts.
Someone who would go through the Monty Hall game to a strangers’ death? Not someone I’d trust in a game of poker played for oreos.
The problem with the Monty Hall problem is that it assumes that Monty knows which door hides the prize, otherwise he might inadvertently eliminate it. As soon as you are deriving information from Monty’s actions it’s no longer a question of raw probabilities. That’s why people have trouble parsing it as a statistical problem — it isn’t really one.
My inability to force this to make intuitive sense is related to your point (I think…)
You’ve opened door 1. Monty knows what’s behind doors 2 and 3. He opens door 2. Door 3 may hide a car. It may also hide another goat, or nothing at all. Monty may have absconded with the car (or the second goat), and is currently imagining the the glorious Albuquerque vacation he’s going to go on with the money.
The thing that got me to understand it was realizing that the problem comes from thinking of the beans individually, rather than as two sets. The one bean you picked (1/3 chance of containing the safe one) and the /entire/ set of other beans (2/3 chance of including the safe one) - and then asking if there’s any way that removing poisonous ones would make the odds of that set /worse/.
Plot twist- they are all poisonous. Or none of them are.
One third chance of survival is still better than first go on a Russian roulette. The problem I have with this problem is that the guy laying out this sick game knows which one will kill the person, so if he wants the person to die he can say all this shit to get him to give up the non lethal jelly bean… unless he’s obliged to make this offer regardless of which one the dude has picked. I’d still try to get a lawyer involved if this happened to me, it seems a bit like so called farmyard justice.
hey nothing to feel bad about, I actually completely understand your attitude and don’t think you’re being an asshole! I just wanted to offer my own perspective, which is that I like the opportunity to be a little smug and self-satisfied around highly intelligent people (so maybe I’m the asshole )
He even carries the beans around in his pocket, ready to whip them out at the drop of a Prunus domestica.
More satisfying than seeing him die, I think, would be feeding him the beans and seeing him not die. “Uh, just messing with you,” he might lamely explain, possibly before admitting it’s not even his farm.
My knowledge of other humans, however, says that there is likely no real life application of this scenario and that therefore the most likely concolusion is that this is a statistics/logic puzzle where statistics and logic are all that count.
But I agree, the original Monty Hall formulation of the problem is superior, because there’s plenty of precedent for game show hosts to actually stick to rules. Monty Hall didn’t have to stick to the rules of the problem, though.
But, let’s assume that poor Wesley has actually been sentenced to death and it doesn’t feel like a logic puzzle any more. Now, what kind of man is that would-be executioner?
An evil person who just wants to see poor Wesley suffer and die. Quite likely, given his behaviour. We can assume him to be a liar as well. All jelly beans might be poisoned. He might stab Wesley to death if the beans didn’t do the trick. He might misdirect Wesley in every way possible to make him swallow a poisonous pill. We’re dead anyway. Close to 0% survival chance either way.
An honest person who values the Arcane Law above anything else. The three-jelly-been-ritual is holy to him. He will tell the truth. 2/3 survival chance if Wesley switches, 1/3 if he doesn’t.
A nice person who really doesn’t want to kill Wesley, but who is compelled by law or by society to go through the motions of punishing Wesley and to do what The Arcane Law demands. He has managed to get three non-poisonous jelly beans, so Wesley gets to go back home to Babylon 5 to resume his life as a homeless teenager in Downbelow to the Enterprise.
The same nice person from 3., but he’s forced to use court-approved jelly beans. He’s afraid that the NSA is recording the conversation, so he’s trying to get away without giving obvious hints if he can get away with it. If he has not dropped any obvious hints, it might be because he trusts boy genius Wesley to know the Monty Hall problem and switch. If Wesley had picked a non-poisonous bean on the first try, then the nice person would have had to drop obvious hints and risk the wrath of the NSA.
)
