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Formula verified · Deterministic calculation

Probability Calculator

Enter probabilities for events A and B to calculate independent intersection, union and the complement of A.

P(A and B), independent0.2
P(A or B), independent0.7
P(not A)0.5
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Result methodology

Combined-event probabilities under the explicit assumption that A and B are independent.

Solution steps
  1. P(A and B) = P(A)P(B) = 0.2
  2. P(A or B) = P(A)+P(B)-P(A and B) = 0.7
  3. P(not A) = 0.5

How this calculator works

For independent events, P(A∩B)=P(A)P(B), P(A∪B)=P(A)+P(B)−P(A∩B), and P(not A)=1−P(A).

Formula

P(A∩B)=P(A)P(B); P(A∪B)=P(A)+P(B)−P(A∩B)

Combines two supplied probabilities under an explicit independence assumption.

Worked example

Independent events is a verified test case used by the calculation engine.

Assumptions and limitations

  • Both supplied probabilities are between 0 and 1.
  • A and B are treated as independent for the combined-event outputs.
  • The calculator does not infer dependence from data.

Methodology & sources

This calculator uses deterministic, versioned calculation logic. The formula and verified examples above are part of the calculation definition used by CalcuMint.

  • CalcuMint deterministic statistics engine

Frequently asked questions

Can I use dependent events?

Not with the independent intersection and union outputs in this certified version.

What does P(not A) mean?

It is the complement of A, calculated as 1 minus P(A).

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