1.1.4.1 Factorial and Techniques of Counting | Fundamental principles of addition and multiplication

In this video, you will get the idea of factorial and its notations. Also you get the logic of fundamental principles of addition and multiplication.
There are two fundamental principles of counting. These two principles solve the problems of counting.

According to Grinstead and Snell (2006) counting is defined as:
“Consider an experiment that takes place in several stages and is such that the number of outcomes m at the nth stage is independent of the outcomes of the previous stages. The number m may be different for different stages. We want to count the number of ways that the entire experiment can be carried out.”

Fundamental Principle of Multiplication (FPM)
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Situation: Two or more jobs to be done sequentially.
When the first job can be done in 𝑚 distinct ways and the second job can be done in 𝑛 distinct ways, then both jobs can take place (one followed by other) in 𝑚×𝑛 distinct ways.

Fundamental Principle of Addition (FPA)
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Situation: One of the two or more jobs to be done.
When the first job can be done in 𝑚 distinct ways and the second job can be done in 𝑛 distinct ways, then one of the two jobs can take place in 𝑚+𝑛 distinct ways.