Probability of an event

P (A) = \frac{|A|}{|Ω|}

|A| - number of ways an event can happen

|Ω| - total number of outcomes

P (A \cup B) = P (A) + P (B) - P (A \cap B)

Probability of an impossible event

P (\emptyset) = 0

Probability of a sure event

P (Ω) = 1

P (\bar{A}) = 1 - P (A)

P (A \cap B) = P (A | B) \cdot P (B) = P (B | A) \cdot P (A)

In cas events A and B are independent

P (A \cap B) = P (A) \cdot P (B)

Keywords: probability of an event, impossible event, sure event, independent event

Probability
Events, Operations with events, Complete system of events
Probability of an event
Conditional Probability
Law of Total Probability
Bayes’ Theorem
Discrete Probability Variable - Distribution Function
Statistics
Measures of Central Tendency
Statistics