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Combinatorics

Definition

Combinatorics is the branch of mathematics dealing with the study of finite or countable discrete structures. It involves counting, arranging, and finding patterns in sets of elements.

5 Must Know Facts For Your Next Test

  1. The Multiplication Rule for Counting states that if one event can occur in 'm' ways and a second can occur independently of the first in 'n' ways, then the two events can occur in 'm x n' ways.
  2. Factorials are frequently used in combinatorics to determine the number of ways to arrange a set of objects.
  3. Permutations are specific arrangements of objects where order matters.
  4. Combinations are selections of objects where order does not matter.
  5. The binomial coefficient, often read as 'n choose k', represents the number of ways to choose 'k' elements from a set of 'n' elements without regard to order.

Review Questions

  • What is the Multiplication Rule for Counting and how is it applied?
  • How do permutations differ from combinations?
  • What is a factorial and how is it used in combinatorics?

Related terms

Factorial (n!): The product of all positive integers up to 'n', used in counting arrangements.

Permutation: An arrangement or ordering of a set where the order matters.

Combination: A selection from a set where order does not matter.



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ยฉ 2024 Fiveable Inc. All rights reserved.

APยฎ and SATยฎ are trademarks registered by the College Board, which is not affiliated with, and does not endorse this website.