BrainTeaser 3

Herbert Dypp · Posted: Mon Jun 09, 2003 7:00 am Post subject: BrainTeaser 3

Your life depends upon the solution you come up with!

You are one of ten prisoners about to be executed. You will be stood in a line one behind another all facing the same direction. You will all be wearing either a white or a black hat.
just a little something to leave you with as I go away....

You can not see the colour of your own hat. You can see the colours of the hats worn by prisoners in front of you. You will each be asked in turn from the back of the line forwards what the colour of your hat is. The only answer you may give is "White!" or "Black!" If you say the correct colour of your hat, you go free. If you say the incorrect colour or anything else, you will be immediately shot!

You have ten minutes to come up with a strategy to save the most people.

What is the best stategy to adopt and how many people can you save?

Wrahn · Member Joined: 04 Feb 2003 Posts: 503

Just wanted to acknowledge I had seen this and am working on it you fiendish little halfling.

Sorgaine · Posted: Tue Jun 10, 2003 5:00 pm Post subject: Re: BrainTeaser 3

I have been thinking about this one also. I have a few questions, though... Is there an equal amount of black and white hats? IE 5 black hats and 5 white hats? Also, can I place the people in the line, or am I already placed in line and if so, where am I in the line? LOL. Do any of these questions make any difference?

BonlainyT · Member Joined: 08 Jan 2003 Posts: 3942

My big question is: Are these convicted felons or POWs? That would make a huge difference in my answer.

Mildane · Posted: Thu Jun 12, 2003 12:00 am Post subject: Re: BrainTeaser 3

Look at the others. See if there is 5 black hats, and 4 white hats, or vice versa. Then look and see if theres a pattern in the hats, like every other one is white, or black. Also, if you get really close to the persons hat in front of you, then you may be able to see a reflection of the color of your hat on their hat (this requires a very high attention to detail). If you dont see a reflection, just a shadow, then you have the same color hat.

For saving others, maybe make a certain type of noise to let each know what color they have on. /shrug, if they dont catch on, at least you tried.

Do not try this at home.

Tryunn · Posted: Sat Jun 14, 2003 10:00 am Post subject: Re: BrainTeaser 3

I'd have to say it kind of depends on where you are in line. If you're standing at the back of the line, then you can probably come up with a plan, but if you're at the front of the line, and can't see what the other prisoners are wearing... I guess you're worm food.

Sorgaine · Posted: Sat Jun 14, 2003 4:00 pm Post subject: Re: BrainTeaser 3

It all depends on if there is an equal amount of black hats to white hats. Assuming that were true, in the back you are all safe. You just see what those are before you and see which color only has 4 vs 5 and that is your color. Then the next person does the same, adding your color hat which is known.

If you are in the front, you can save yourself, but you can't save the others.

I guess we need a little clarification on this one? Where are we in the line? Can we make the lineup ourselves? Is there an equal amount of black to white hats?

Herbert Dypp · Posted: Tue Jun 24, 2003 11:00 pm Post subject: Re: BrainTeaser 3

sorry to pose this and disappear for two weeks...I'll give a couple of clues..

1) it works regardless of whether there is a 50-50 split of black to white.

2) it is not possible to be 100% sure of saving everyone.

Wrahn · Member Joined: 04 Feb 2003 Posts: 503

Yeah, I had this one sitting on the back burner for a while. I will post an answer, when I have more time and I can completely run through it.

MalkarDiesalot · Posted: Sun Jul 06, 2003 8:00 am Post subject: Re: BrainTeaser 3

the guy at the back calls the color of the 1st person...the 9th guyy calls the 2nd guy's color and so on...you'd at least save half the people..by the time you get to the middle guy the front 5 in the line know what they are wearing and if your group of people is really lucky then maybe a few in the back had the color of the guy they called out...

just a quick quess...

Sorgaine · Posted: Sun Jul 06, 2003 9:00 am Post subject: Re: BrainTeaser 3

Hey! Good guess! I bet that's it...

Herbert Dypp · Posted: Mon Jul 07, 2003 12:00 am Post subject: Re: BrainTeaser 3

good try. you'll save 5 for sure and have a 50-50chance of saving the other 5.

hint: it is possible to save 9 for sure....

MalkarDiesalot · Posted: Mon Jul 07, 2003 7:00 am Post subject: Re: BrainTeaser 3

ok, looking at this from a different angle...I notice you keep saying each prisoner will be asked for the color of "your" hat, not the color of "thier" hat...Just have the 1st guy yell either white or black...If he yells white and lives then everyone knows "your" hat is white, if he yells white and dies then everyone knows "your" hat is black...

I may be reading way to into that but it seems to make sense to me <img src=

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Herbert Dypp · Posted: Tue Jul 08, 2003 5:00 am Post subject: Re: BrainTeaser 3

malkar, there is no little catch like that Smile

Guest · Posted: Fri Sep 05, 2003 10:47 am Post subject:

You call out the colour of the hat in frount of you?