Determine the number of its n-combinations

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Discussion Overview

The discussion revolves around determining the number of n-combinations from a specific multiset defined as {n*a, n*b, 1, 2, 3,..., n+1}, which has a size of 3n + 1. Participants explore the size of the multiset and clarify the elements involved.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant presents the multiset and seeks assistance in determining the number of n-combinations.
  • Another participant questions the calculation of the multiset's size, suggesting it should be n + 3 instead of 3n + 1.
  • A third participant provides a specific case for n=2, confirming that the multiset contains 7 elements, thus supporting the original claim of size 3n + 1.
  • A later post indicates that the problem has been resolved, raising a question about the thread's deletion.

Areas of Agreement / Disagreement

There is disagreement regarding the size of the multiset, with one participant questioning the original claim while another provides a specific example that supports it. The discussion does not reach a consensus on the initial question posed.

Contextual Notes

The discussion includes a potential misunderstanding of the multiset's size and its implications for determining n-combinations, but these points remain unresolved.

Jrb599
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Consider the multiset {n*a, n*b, 1, 2 , 3,..., n+1} of size 3n + 1. Determine the number of its n-combinations.

I'm stuck on this one, any help would great.
 
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How is its size 3n+1 and not n+3?
 
Consider the case n=2

you get

(a,a,b,b 1,2,3) which gives you 7 elements

not 5, so 3n + 1 holds.
 
PRoblem solved, will this thread be deleted?
 

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