probabilities and infinity (was Re: virus: Real World?)

David McFadzean (
Mon, 06 Jan 1997 17:40:56 -0700

At 03:30 PM 06/01/97 GMT, wrote:
>> By the same reasoning, if
>> I flip a coin twice the chances of getting tails is 100% (1/2 * 2 = 1/1).
>Not true, but if you flip a coin an infinite amount of times, you will get
>tails an infinite amount of times. You will also get heads an infinite
>amount of times - I think ;P

What I was trying to get at was that for a positive integer n,
where you have a probability of 1/n of success and n trials,
if n -> oo, the probabilty of getting one or more successes
approaches 1-(1/e) =~ 63% (not 100% as your drunk friend was

So for you RPGers out there, if I roll percentile dice 100 times,
there is about a 63% chance of rolling double zeros. If I roll the
same dice 1000 times, there is over a 99.996% chance of double zeros.
But I'd have to roll them an infinite number of times to get a 100%

David McFadzean       
Memetic Engineer      
Church of Virus