So if we want to calculate the exact probability
of an event occurring
how do we do it in general?
To see how, we will need some notation.
**Notation** P(A) is the probability that event A
will occur.
P(A) = __
The number of ways event A can occur
.__
The total possible number of ways all outcomes can occur
**General properties of probability**
1) P(A)=1 means event A **must** occur
(100% chance A will occur)
2) P(A)=0 means event A **can not** occur
(0% chance A will occur)
3) Otherwise 0 < P(A) < 1