Date: Dec 27, 2012 6:08 AM
Author: quasi
Subject: Re: Probability Pill

quasi wrote:
>William Elliot wrote:
>

>>Each day I take 1/2 an aspirin tablet. I bought a bottle of
>>100 tablets; each day I take out one, if it's whole I break
>>it half and eat a half and put the other half back: if I pull
>>out a half tablet I eat it. I was wondering after I break the
>>last whole one what the expected number of halves are in the
>>bottle? I assume that any piece I pull out has uniform
>>probability.

>
>I suspect that the above question is not actually yours.
>
>If that's the case, what is the actual source?
>
>Is it from a poster in another forum? If so, why do you omit
>mention of the poster and the forum?
>
>Is it from a book or math contest?
>
>Why do you repeatedly post questions that are not your own
>without giving credit to the source?
>
>In any case, the expected number of halves left when the last
>whole pill is split is
>
> (199!) / ((4^99)*((99!)^2))


Which is slightly more than 11 half pills.

quasi