Ooops, the formula doesn't work for small n and m. Consider n=2 and m=2.
Each man will have at least one woman by his side no matter how you arrange
them, so the expected number of men that will have at least one woman by his
side is 2.00, and the probability of at least one woman by the side of a
given man is 1.00. The formula says p = (2m)/(n+m-1) = (2x2)/(2+2-1) = 4/3
= 1.33! The expected number of women by the side of a given man is 1.33.
Dale Berger
----- Original Message -----
From: Kenn Konstabel <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, December 19, 2000 6:27 AM
Subject: Re: a brainteaser
> Elvis Rodriguez wrote:
>
> > Can anyone help with this?
> >
> > n men and m women are sitting around a ruond table. What is the
> > Expected number of men that will have at least one woman by his side?
>
> provided that they sit randomly, the probability that a randomly selected
> man has at least one woman by his side should be (2m)/(n+m-1) ? you can
> multiply it by n to get the expected number you want.
>
> k
>
>
>
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