Hey I got a logical puzzle for you! Why do Chinese bury their dead with their ass sticking out of the ground?

how can the optimal strategy give a chance of 1% if there is no communication and the first person only has a 1% chance of survival? i understand how through a strategy the odds are better for every prisoner after the first one, yet surely the chance of survival for the whole group goes down with every prisoner that undertakes the challenge?

I promise that it is true Socrates.

@Zmaj is this a joke or a puzzle?

The only possible strategy would be for each prisoner who made it through to mark his box so the next would know the box(es) that weren't his own. He might be able to do it with special foot marks in the dirt floor but those could be erased on the reset.

Well... a logic joke, I guess... the Gordian Butt, so to speak.

@Draug- No marking, no communication, no nothing. The room is completely reset to its original state.

my last hope before i give up is to somehow mark the box of the next person, however this is communication surely? if it is even allowed, which i doubt... this is frustrating!
@Zmaj, unless ass=donkey in which case it would be self evident why the bury the dead with their ass out the ground, I'm going to have to give up on yours too!

I'll throw one out while we struggle with uclabb's, but it's similar enough that he probably knows the answer to this one too.

A king has 100 prisoners, numbered 1-100 (these ones don't get names because this king is less humane). He puts each number in a box and puts all 100 boxes in a room. Each prisoner will go into the room and open 50 boxes. If he doesn't find his number, they all die. If he does, the next prisoner goes. What is the optimal box opening strategy?

can the first prisoner erase/take out the other names as he goes for yours (uclabb)?

@ghug- I do know the answer to this one... Do you? The answers are very similar.

@Socrates - I'm not sure what you mean by that, but the first prisoner has absolutely no affect on what the second prisoner sees when he goes into the room. Everything is reset.

I do. I figured it out in about 5 minutes when I first heard it, it's part of the reason this one is bugging me so much.

Send in the guard.

What I meant is that the names are inside the boxes and the prisoners die if their names are inside said boxes, is there a way for the first prisoner to get rid of the names inside of the boxes? (technically not something the second prisoner sees upon entering the room). I'm guessing from your response the answer is no. I'm off her for a bit, hopefully someone will have better luck than I!

The answer to your problem that you know gives something like a 30 percent chance of success, right ghug?

Yeah, I think that's about right.

Hmmm... Then (not to rub salt in the wound but) I'm surprised the answer to my question is eluding you. It seems to me that my question is strictly easier than that one.

To make the parallel 100% clear, my question could be stated:

A king has 100 prisoners, numbered 1-100 (these ones don't get names because this king is less humane). He puts each number in a box and puts all 100 boxes in a room. Each prisoner will go into the room and open 99 boxes. If he finds his number, they all die. If he doesn't, the next prisoner goes. What is the optimal box opening strategy?

Is there a better one?

No, for your question, I'm pretty sure the best answer succeeds about 31.18% of the time

He doesn't look in the boxes, he just opens them.

You are upstairs in a room with no windows and 3 light switches. There are 3 incandescent lights in the basement of this building. You know all three lights are currently off. You can flip the switches as many times as you like, but you may only go downstairs once. You have no idea which switch controls which light. How do you figure out what lights the 3 switches control. Each switch only controls one light.

This is a a semi common one, if you have seen this before please don't reply.

I'm going to throw this one up again as well, no looking back at the old forum thread or answering if you remember it or are uclabb (as he figured it out before, I think).

There are three spiders and a fly moving along the edges of a regular tetrahedron (edges, not faces). The spiders are given a completely deterministic set of orders for catching the fly, and the fly is given access to that set of orders ahead of time. The fly is completely impossible to detect by the spiders until caught, and can choose its starting location given the starting locations of the spiders, but moves slightly slower than the spiders (how much slower is irrelevant). What set of orders ensures that the spiders catch the fly?

Turn on the first two for some time. Turn off #1. Go downstairs and feel the lights. The one on is switch #2, the one off but hot is switch #1 and the cool one is switch #3.

Draug, I am completely sure that you already knew that one and chose to answer anyway.

Then you would be completely wrong. I thought for a moment and "hot bulb!" popped into my head.

It was an easy one, quite honestly.

But remember, I solve problems for a living (software developer).