Probability is the chanse of something happening.
Ex 1: The Probability of getting a 3 on a 6-dice is 1/6.
Ex 2: The probablity of of raining in Sahara Desert is very low.
In mathematics there are four basic rules:
- For any event A, 0 ≤ P(A) ≤ 1.
- P(impossible event) = 0. Also written P(empty set) = 0 or P() = 0.
- P(sure event) = 1. Also written P(S) = 1, where S is the sample space.
- P(not A) = 1 – P(A). Also written P(complement of A) = 1 – P(A) or P(A^C) = 1 – P(A) or P(Â) = 1 - P(A)
If all outcomes of an experiment are equally likely, then:
P(A) = number of outcomes in event A / number of outcomes in the sample space