Probability Calculator

Calculate probabilities for various scenarios with visualizations

Single Event Probability

Example: Probability of rolling a 3 on a fair die

Favorable outcomes: 1 (only the number 3)

Total outcomes: 6 (numbers 1 through 6)

Probability Rules & Formulas

Basic Rules

0 ≤ P(A) ≤ 1
P(S) = 1
P(∅) = 0

S: Sample Space, ∅: Empty Set

Complement Rule

P(A') = 1 - P(A)

A': Complement of A

Addition Rule

P(A∪B) = P(A) + P(B) - P(A∩B)

For mutually exclusive: P(A∩B) = 0

Multiplication Rule

P(A∩B) = P(A) × P(B|A)

For independent: P(A∩B) = P(A) × P(B)

Probability measures the likelihood of an event occurring, ranging from 0 (impossible) to 1 (certain).