MHB Placing Balls in Numbered and Unnumbered Boxes: Infinite Possibilities

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The discussion centers on a combinatorial problem involving placing infinite identical balls into a set of numbered and unnumbered boxes. For numbered boxes, the total ways to fill them is calculated as (n+1)^n, accounting for the capacity of each box. When boxes are unnumbered, the problem shifts to determining unique sets of objects, leading to a more complex formula involving Stirling numbers. Participants clarify assumptions about the indistinguishability of the balls and explore the implications of these assumptions on the number of arrangements. The conversation concludes with a confirmation of the derived formulas for both scenarios.
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Hey! (Giggle)

I am given this exercise:
If we have a pile of infinite balls and $n$ numbered boxes with a capacity of $n$ balls each one,with how many ways can we place some balls in the boxes?Answer the same question,if the boxes are not numbered.

Could you give me a hint what to do?? :rolleyes: (Blush)
 
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Is it maybe $n^n$ ?? Or am I wrong? :confused:
 
evinda said:
Hey! (Giggle)

I am given this exercise:
If we have a pile of infinite balls and $n$ numbered boxes with a capacity of $n$ balls each one,with how many ways can we place some balls in the boxes?Answer the same question,if the boxes are not numbered.

Could you give me a hint what to do?? :rolleyes: (Blush)

evinda said:
Is it maybe $n^n$ ?? Or am I wrong? :confused:

Hi! (Smirk)

How did you get $n^n$?
 
I like Serena said:
Hi! (Smirk)

How did you get $n^n$?

I thought it,because of the fact that there are $n$ numbered boxes,and at each one we can put $n$ balls..Is it wrong?? :confused: (Thinking)
 
evinda said:
I thought it,because of the fact that there are $n$ numbered boxes,and at each one we can put $n$ balls..Is it wrong?? :confused: (Thinking)

Let's start with 1 box that can contain $n=3$ balls.
What are the possibilities to fill it? (Wondering)
 
I like Serena said:
Let's start with 1 box that can contain $n=3$ balls.
What are the possibilities to fill it? (Wondering)

With infinite balls,or not?? :confused:
 
evinda said:
With infinite balls,or not?? :confused:

Yes. (Wasntme)
And I guess we'll have to assume those infinite balls are identical, or the problem becomes a bit non-sensical otherwise.
 
I like Serena said:
Yes. (Wasntme)
And I guess we'll have to assume those infinite balls are identical, or the problem becomes a bit non-sensical otherwise.

So,are there infinite ways?? :eek: Or is there an other formula,that expresses it?? (Thinking)(Thinking)
 
evinda said:
So,are there infinite ways?? :eek: Or is there an other formula,that expresses it?? (Thinking)(Thinking)

If the infinite balls are unique, there would indeed be infinite ways.
That is why I am assuming that they can not be distinguished from each other. (Wink)

So 1 box with capacity 3 could for instance contains 3 balls.
What are the other possibilities?
How many are those?
 
  • #10
I like Serena said:
If the infinite balls are unique, there would indeed be infinite ways.
That is why I am assuming that they can not be distinguished from each other. (Wink)

So 1 box with capacity 3 could for instance contains 3 balls.
What are the other possibilities?
How many are those?

So,is it also possible that 1 box contains also $2$, $1$ or $0$ balls?
But how can I find then the number of ways we can place some balls in the boxes?? (Thinking)
 
  • #11
evinda said:
So,is it also possible that 1 box contains also $2$, $1$ or $0$ balls?
But how can I find then the number of ways we can place some balls in the boxes?? (Thinking)

Now I am going to assume the box does not have specific places for the balls, but that it just contain a number of balls.

So for 1 box with capacity $n=3$ we have $4$ ways to fill it... (Thinking)
 
  • #12
I like Serena said:
Now I am going to assume the box does not have specific places for the balls, but that the just contain a number of balls.

So for 1 box with capacity $n=3$ we have $4$ ways to fill it... (Thinking)

So,one box with capacity $n$ has $n+1$ ways to be filled.So,in general, $n$ boxes have $(n+1)^n$ ways to be filled,right?? :rolleyes:
 
  • #13
evinda said:
So,one box with capacity $n$ has $n+1$ ways to be filled.So,in general, $n$ boxes have $(n+1)^n$ ways to be filled,right?? :rolleyes:

Right! (Cool)
 
  • #14
I like Serena said:
Right! (Cool)

Great!Thank you very much! (Clapping)
 
  • #15
evinda said:
Hey! (Giggle)

I am given this exercise:
If we have a pile of infinite balls and $n$ numbered boxes with a capacity of $n$ balls each one,with how many ways can we place some balls in the boxes?Answer the same question,if the boxes are not numbered.

For the second question, I interpret this as being equivalent to asking: "how many unique sets of n objects can be formed by selecting zero or more of each of n distinct symbols".

So, for n=2 we have R(2)=3: aa, ab, bb

and in general, for n>3, we have:
\[R(n)=\sum_{m=1}^{n}mS(n-m+1)=R(n-1)+\sum_{m=1}^{n}S(m)\]

where \[S(n)=\sum_{k=1}^{n}k=\frac{n(n+1)}{2}\]
 
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