Sven's Official BrainTeaser Thread !! and Sander.

[SvenF]

I just thought if someone feels like to post a new riddle, just go ahead:)

[a;sdlfkjas;df]

alright, an easier prison puzzle:

a prisoner has a chance to gain his freedom.  the warden states that the prisoner will be allowed to choose a ball from one of two jars.  if he chooses a white ball, he will gain his freedom.  if he chooses a black ball, he will be killed.  by a stroke of luck, he is left alone with the jars before he chooses.  the jars will be shuffled before he can choose.  he will not be able to mark the jars and consequently will not remember which one is which.  one jar contains 50 white balls.  the other contains 50 black balls.  he can shuffle the balls around at his leisure.  the warden will not know if a jar contains 50 balls or 99 balls.  right now, he has a 50/50 chance of survival.  how does he increase his odds?

[Sander]

remove all black balls?

[a;sdlfkjas;df]

 :lol:

well, for how the puzzle is written, that would be the correct answer, but that is my mistake

"solve" it under the condition that no ball can be removed

[Sander]

okay, put 1 white ball in one jar and all the others in the other jar. then in the first jar the chance of survive will be 100% and in the second one 49,5%. then he will have an overall chance of (100+49,5)/2=74,75% chance of survival

[a;sdlfkjas;df]

correct  :thumbsup:

[Mike]

In a country, the percentage of people with blond hair of the people with blue eyes is bigger than the percentage of blond hair of the whole population.
Is the percentage of people that are having both blond hair and blue eyes of all blond haired bigger, smaller or equal to the percentage of the blue eyed people of the whole population?

I hope I did not confuse anyone.

[a;sdlfkjas;df]

larger?

[sputnik]

you should probably say your reasoning so it doesnt look like a guess

ps mike your wording is hard to understand

[a;sdlfkjas;df]

people with blonde hair compose a disproportionally large portion of people with blue eyes.  i transferred that to his question

[sputnik]

i dont think thats the logic... i assume you could replace blond hair and blue eyes with anything, even X & Y

[Sander]

you don't know how much people there are with non-blonde hair and blue eyes, therefore you can't know the answer