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A thirst to understand

Member

Registered: 2009-04-08

Posts: 2

Attempting to understand my 16 year old friend..

I have a friend, who is 16 and always succeeds in confusing everyone around him. i however at least attempt to untangle his insaneness. today he was talking about probability formulas and something like quantum uncertainty. the situation was; a man has a choice between three doors, an object is behind one door. the man has chosen a door, what is the probability of the object being behind his chosen door, My 14-year old, algebra one brain instantly jumps to 1/3!! but he said that the assumption was 1/2 but it was actually 2/3..... i have been pondering for the last few hours, i think i have come up with something, but i was hoping for some sort of clarification in any way, some sort of base, he said something about looking up formulas...but im lost! i would appreciate if someone would help.

luca-deltodesco

Member

Registered: 2006-05-05

Posts: 1,470

Re: Attempting to understand my 16 year old friend..

He is inccorect:

the probablity is 1/3

He is misinterpreting/misquoting the Monty Hall / 3 Prisoners Problem of which his question is more related to the Monty Hall problem:

http://en.wikipedia.org/wiki/Monty_Hall_problem

In the Monty Hall problem, the player picks a door, and the host of the game, then picks one of the other two doors that ISN'T the prize, the probability of winning if you switch your door to the other available one is then increased from 1/3 to 2/3 as a result of the host's actions:

if the host does not give the player any information, or open one of the loosing doors, then the probablity is still 1/3 no matter which door you pick

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A thirst to understand

Member

Registered: 2009-04-08

Posts: 2

Re: Attempting to understand my 16 year old friend..

ahh now i see why i almost died trying to get the formula to spit out 2/3
anyway it was a good challenge to at least try and understand it. well thanks