State the Axiom of probability
There are 3 Axioms of Probability:
1) $\displaystyle P(\Omega) = 1$
2) If $\displaystyle A$ is inside $\displaystyle \Omega$ then $\displaystyle P(A) \geq 0$
3) If $\displaystyle A_1$ and $\displaystyle A_2$ are disjoint then $\displaystyle P(A_1 \cup A_2 ) = P(A_1 ) + P(A_2 )$