Combinations are just an application of the counting principle?

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Discussion Overview

The discussion centers around the relationship between combinations and the counting principle, exploring whether combinations can be considered an application of this principle. Participants examine definitions and formulas related to counting outcomes in various scenarios, including permutations and combinations.

Discussion Character

  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant suggests that combinations may be viewed as an application of the counting principle, similar to how permutations relate to the fundamental principle of counting.
  • Another participant seeks clarification on what is meant by "the counting principle."
  • A participant defines the counting principle as a method for determining the number of possible outcomes when multiple events occur.
  • Further elaboration on the counting principle includes formulas for multiplication and addition of choices, indicating that combinations and permutations can be seen as applications of this principle.
  • A specific formula for combinations is presented: \(\frac{N!}{K!(N-K)!}\), and for permutations: \(\frac{N!}{(N-K)!}\).
  • One participant expresses gratitude for the explanations provided, indicating that the information helped clarify their understanding.

Areas of Agreement / Disagreement

Participants appear to agree on the definitions and applications of the counting principle, but the discussion does not reach a consensus on whether combinations are definitively an application of this principle, as the initial question remains open-ended.

Contextual Notes

Some assumptions about the definitions of combinations, permutations, and the counting principle are not explicitly stated, which may affect the clarity of the discussion.

skrying
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Is it fair to say combinations are just an application of the counting principle? I already understand that permutations are just an application of fundamental principle and that combinations are just an application of permutations. If it's fair to say that combinations are in fact, just an application of the counting principle, then would their be a specific formula that proves as such? :!)
 
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Pardon my ignorance. What is "the counting principle"?
 
The counting principle

The counting principle is dealing with the occurrence of more than one event, thus being able to quickly determine how many possible outcomes exist.
Kind of like sequences, if that makes more sense.
 
Counting principal for multiplication is: If something can be done in A ways and something else can be done in B ways, then the entire event can be done in AB ways.
For addition it means that in disjoint sets A and B, if we have K choices in A and L choices in B, then we have K+L choices in A union B.

Combinations and permutations then seem to be just that, applications of the counting principal. Possibly, skrying is aware that the combinations of N things taken K at a time is:

[tex]\frac{N!}{K!(N-K)!}[/tex] And for permutations: [tex]\frac{N!}{(N-K)!}[/tex]
 
Last edited:
Thank you Robert

Thank you Robert, that explanation and the examples were really helpful. You explained it so it actually "makes sense" to me. Much appreciated! :smile:
 

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