Union Probability Calculator

Calculate the probability that at least one of two events occurs using the addition rule.

P(A or B)

0.700000

P(A or B) as %70.0000
P(Neither)0.300000

P(A or B) vs P(A)

Voir la formule →

Formule

## How to Calculate Union Probability ### Formula **P(A or B) = P(A) + P(B) - P(A and B)** The addition rule accounts for the overlap between events A and B. If you simply add P(A) and P(B), the intersection is counted twice, so you subtract P(A and B) once. For mutually exclusive events, P(A and B) = 0.

Exemple Résolu

P(A) = 0.3, P(B) = 0.5, P(A and B) = 0.1. Find P(A or B).

  1. 01P(A or B) = P(A) + P(B) - P(A and B)
  2. 02P(A or B) = 0.3 + 0.5 - 0.1
  3. 03P(A or B) = 0.7
  4. 04P(Neither) = 1 - 0.7 = 0.3