Nice ideas, but no. ;P The goats don't move, and there's a purely mathematical reason why he should choose Door C.
Hint: Think about probability. At the start, there is a 1/3 probability that each door has the car.
This is a pretty tricky one, and actually when it was first published on the internet there was an accomplished mathematician who swore that everyone was wrong and that it doesn't make a difference whether you stay with Door A or switch to Door C. She was eventually proven wrong, to her great embarrassment. ;P
13 years ago
Sun Aug 08 2010, 01:07pm
Okay.......
My try :P
Initially, before the host opens the door, there is a 1/3 chance that each door had the car.
All possibilities are:
A:B:C:
G G C
[strike]G C G[/strike]
C G G
Stay: Switch
G______C
G______C
C______G
1/3 vs 2/3
That means by choosing Door A; you have a 1/3 chance of choosing the car; and there is a 2/3 chance that doors B and C contain the car.
The second possibility is struck out when the host opens Door B. That means choosing Door A, you still have a 1/3 chance of choosing the car; and there is a combined 2/3 chance that car is behind Door B and C.
Therefore, since there is a higher chance of choosing the car behind the combined doors B and C; you should switch to C.
Supposing that you stayed with A and A had the car all along, if you switched, you would have a 1/3 chance of being wrong by switching.
THe hard part is getting over the fact that there IS NOT a 1/2 probability each that behind A and C there is a car. The probability for A having the car STAYS at 1/3. There is no "redistribution" of the probability once the host has revealed the goat behind Door B. It only means that the 1/3 probability that it could have been B, gets added to the non-chosen door C, which means the probability of C having the car increases.
That was a long and mathematical explanation Mono. I think I understand what you were saying.
I thought it was the moon for number two of your ones Ahra...
Mono's explanation is right for my riddle. :nod:
ok first of, wow that explanation was tricky and you almost lost me, but the end part makes sense!
arha is the answer to two dusk, or maybe dawn?
Agyllian i am going to take another wild guess, ok so i think for the capture one that NONE of them have a chance. Because . . . The evil twisted devil captain wants them all dead so he kills them all of one by one, cause the one behind is the only one who can see the one in front, an they get killed first. Sorry if that is confusing and way of! ;D
Ashlings' guildleader
13 years ago
Ashlings' guildleader
Master of Obernewtyn
hmm, maybe I shouldn't have made him so evil ;D ... I like your answer but it's not the one I'm looking for.
13 years ago
Mon Aug 09 2010, 05:35pm
To Agyllian's first problem:
The prisoner at the end of the line counts the number of black hats in front of him. If there is an odd number of black hats, he says 'My hat is black'. If there's an even number of black hats, he says 'My hat is white'.
For example, assume that there's an odd number of black hats, and the prisoner says 'My hat is black'.
Assuming that he was wrong, he would be killed. The next prisoner in line would then know that there is an odd number of black hats. So he counts the number of black hats in front of him, and if there's an even number, he says 'My hat is black'. If there's an odd number, he says 'My hat is white'.
And so on, with each person working out whether there is an even or odd number of black hats, counting the number of black hats in front of them, and thus working out the colour of their own hat.
Therefore, 4 people would definitely be saved, and the first person would have a 50% chance of survival.
I hope that made sense. :P
I'm not sure about Problem 2. I'll have a think about it. :nod:
[ligne][/ligne]
I have another riddle as well. I can't remember whether it's been discussed here before or not, but oh well. :P
There is an island with only 3 inhabitants. On this island, there are 2 blue-eyed people and 1 brown-eyed person. The people on the island know that they either have blue or brown eyes, but they don't know what colour their own eyes are. It's considered taboo to know the colour of your own eyes, and if you find out what eye colour you have, you have to kill yourself that night.
One morning, a blue-eyed stranger arrives on the island. He looks around and says; "I'm so glad to be on an island where there's one or more person with the same colour eyes as me."
The question is: What happens, and how long does it take to happen?
beth your right ;D its dusk and dawn
Ashlings' guildleader
13 years ago
Ashlings' guildleader
Master of Obernewtyn
Avialle is correct. If you want it Avialle, here is a clue for the second part:
If instead of counting the number of a certain type of hat, you assign a number to each the black and white hats (say white=1, black=0), then try and work out how that can be used to solve the first problem. I think you;ll see pretty quickly then how to apply it to the second part
For your new problem Avialle, is the answer like this? I think the traveller would have said "I'm so glad to be on an island where there's one person with the same colour eyes as me." if their had have been only one with blue eyes. The or more, although technically doesn't exclude the possibility that there is only one other with the same coloured eyes, would suggest there is more than one other with the same coloured eyes. Both the blue people can see that either one of them each has blue eyes and that the other person has brown eyes. So the blue eyed people would come to the conclusion that they are in the majority with the stranger. With that, both of the blue eyed people would kill themselves at the same time. Seeing this, the brown eyed person would question how the two newly deceased both knew they had blue eyes. He would then understand that for them to reach that conclusion, he must have brown eyes for the other two to reach their deductions. He would then kill himself.
I feel I might have missed a step of logic though :P
Meza that is one version =D.........but not the one im thinking of........there is no fish! and u are incredibly close!
another 1 my friend gave me......
There are three girls who are having a sleepover and all three bring identical umbrellas and leave them sitting upright in a stand. the girls dont know which ones which, so what percentage chance is there that two of the girls will walk off with their own umbrella?
Arha: ok so that one about the umbrellas really confusing me at first, because if two girls DO walk of with the same umbrella then the other girl HAS to have her own one as well. Then i realized that it must be the answer. So i think it must be that there is a 0% chance.
Here is one that i think my ICT teacher told me in year eight.
A glass jar holds one germ. After one minute, the germ splits into two germs. A minute after that, the two germs each split again, forming a total of four germs. Continuing at this rate, a single germ can multiply to fill a whole jar in exactly one hour. Knowing this, how long in minutes would it take to fill the jar if you had started with two germs?
To Beth's problem:
It would take 59 minutes. You save the first minute, because there are already two germs. (So you save the minute that was required for the single germ to split into two). After that, the germs keep multiplying as usual.
I thought I'd post one here. . .
There is a man trapped in a house. There are no windows, no doors not even a chimney. Just the man and a table. How does he get out?
He beats his hand against the wall until it becomes sore. He grabs the saw and cuts the table into two halves. Two halves make one whole. He jumps into the hole and screams until his voice gets hoarse. Jumps onto the horse and rides away.
hehe, yep! the answer is 0%!
13 years ago
Mon Aug 23 2010, 05:10pm
Tonks, that's very very close! But he doesn't beat his hand on the wall.
Hmm... can I post a riddle. It's not really a riddle I suppose it is just sorta interesting. Well... to me anyway. You might of already heard of it.
WITH THE 98%..THIS IS TRULY TRIPPY
At the end of this message, you will be asked a question. Answer it
immediately. Don't stop and think about it. Just say the first thing that pops into your mind..
This is a fun 'test'.. AND kind of spooky at the same time! Give it a try,
Be sure to put in your next post if you are among the 98% or the 2%. You'll understand what that means after you finish taking the 'test.'
Now - just follow the instructions as quickly as possible. Do not go to the
next calculation before you have finished the previous one. You do not ever
need to write or remember the answers, just do it using your mind.
You'll be surprised.
Start: How much is: 15 + 6
21
3 + 56
59
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> I know! Calculations are hard work, but it's nearly over ......
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> QUICK! THINK ABOUT A COLOR AND A TOOL!
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> Scroll further to the bottom .....
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> You just thought about a red hammer, didn't you?
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> 98% of the folks answer a red hammer while doing this exercise.
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well i got an orange spanner so i guess i am in the 2%, but range is pretty close to the colour red so i wasn't to far of.
Those questions are so weird, especially when everyone gets the same answer! How does it work!!?
sorta like, think of any vegetable and the first on that comes to mind is a carrot.
I thought of a pink screwdriver! :D *highfives Bth* Go us!