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Subject: "Probability Problem"     Previous Topic | Next Topic
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Zloty Lojak
guest
Apr-12-08, 07:55 AM (EST)
 
"Probability Problem"
 
   I have a tough question I cant get the answer for:
I have L hats and N balls (N<L) each hat can contain 0,1 or 2 balls, not more than 2. all N balls are spread among the L hats (randomly). what is the probability of a certein hat to have 1 ball and what is the probability of a certain hat to have 2 balls?


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Mark Huber
guest
Apr-14-08, 11:00 AM (EST)
 
1. "RE: Probability Problem"
In response to message #0
 
   >I have a tough question I cant get the answer for:
>I have L hats and N balls (N<L) each hat can contain 0,1 or
>2 balls, not more than 2. all N balls are spread among the L
>hats (randomly). what is the probability of a certein hat to
>have 1 ball and what is the probability of a certain hat to
>have 2 balls?

There's lots of different ways to "randomly" spread the balls among the hats. For instance, you could take the balls one at a time, pick a hat with equal probability among the hats that have fewer than 2 balls in them, and drop the ball in that hat.

Another method would be to choose uniformly (so with equal probability) among all assignments of x_1,...,x_L, where x_i is either 0, 1 or 2, so that x_1 + x_2 + ... + x_L = N.

And there are many other methods. Could you give more details about the method in your question?

Mark


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