## Probability Formula:

$$\text{P(A)}\;=\;\frac{\text{Number of Favorable Outcome}}{\text{Total Number of Favorable Outcomes}}$$

**Or**

$$\text{P(A)}\;=\;\frac{\text{n(E)}}{\text{n(S)}}$$

**Where,**

**P(A)** shows probability of an event.

**n(E)** shows number of favorable outcomes.

**n(S)** is the total number of events in the sample space.

## Some Basic Probability Formulas

Suppose that the A and B are two events.

Probability Range | 0 ≤ P(A) ≤ 1 |

Addition | P(A∪B) = P(A) + P(B) – P(A∩B) |

Complementary Events | P(A’) + P(A) = 1 |

Disjoint Events | P(A∩B) = 0 |

Independent Events | P(A∩B) = P(A) ⋅ P(B) |

Conditional Probability | P(A | B) = P(A∩B) / P(B) |

Bayes Formula | P(A | B) = P(B | A) ⋅ P(A) / P(B) |