what is Counting Principles

Aug 08, 2022, 16:45 IST

Counting Principles

There are two fundamental counting principles viz. Multiplication principle and Addition principle. 

Multiplication Principle

If one experiment has n possible outcomes and another experiment has m possible outcomes, then there are m  n possible outcomes when both of these experiments are performed.

Addition Principle

If one experiment has n possible outcomes and another has m possible outcomes, then there are (m + n) possible outcomes when exactly one of these experiments is performed. In other words, if a job can be done by n different methods and for the first method there are a1 ways, for the second method there are a2 ways and so on . . . for the nth method, an ways, then the number of ways to get the job done is (a1 + a2 + ... + an).