Probability of 3 Events Calculator

Combine three independent event probabilities.

P(A and B and C) 0.06

P(A or B or C) 0.79

Formula: all = A·B·C; any = 1 − (1−A)(1−B)(1−C)

Step-by-step with your numbers:

1. Values used:

2. P(A) = 0.5

3. P(B) = 0.4

4. P(C) = 0.3

6. P(A and B and C) = P(A) x P(B) x P(C) = 0.5 x 0.4 x 0.3 = 0.06

7. P(A or B or C) = 0.79

Did we solve your problem today?

For independent events, combine probabilities by multiplying (AND) or complementing (OR).

The math behind it

P(all) = A·B·C. P(at least one) = 1 − (1−A)(1−B)(1−C).

0.5, 0.4, 0.3 → all 0.06, any 0.79.

Does this need independence?

Yes — for dependent events use conditional probabilities.