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Fundamental Counting Principle


Mike McGarry
Lesson by Mike McGarry
Magoosh Expert

Summary
The Fundamental Counting Principle is a cornerstone concept for understanding how to calculate the number of ways a task can be completed when it can be divided into stages, with each stage having a set number of choices.
  • The principle is based on the idea that the word 'and' implies multiplication, allowing for the calculation of total outcomes by multiplying the number of choices available at each stage.
  • Examples provided include calculating the number of possible meals at a formal dinner and the number of ways books can be arranged on a shelf, illustrating the principle's application in different scenarios.
  • The principle extends to arranging n different items in order, with the total number of arrangements being the product of n and every positive integer less than n, a concept that will be formalized with the introduction of factorials.
  • A practice problem involving the selection of a company's steering committee demonstrates how quickly numbers can grow in combinatorial problems, highlighting the principle's utility in solving complex counting tasks.
Chapters
00:01
Introduction to the Fundamental Counting Principle
01:03
Applying the Principle to Real-World Scenarios
02:16
Extending the Principle to Arrangements and Orders
04:52
Practice Problem: Steering Committee Selection