TATITIC CALCULATOR
Probability Calculator
A precise tool.
What is the Probability Calculator & How does it work?
Probability quantifies the likelihood of an event occurring, expressed as a number between 0 (impossible) and 1 (certain). Understanding how individual event probabilities combine is essential for risk assessment and decision‑making.
When two events A and B are not mutually exclusive, the probability that either occurs is given by the inclusion‑exclusion principle. This accounts for the overlap where both events happen simultaneously.
P(A cup B) = P(A) + P(B) – P(A cap B)
P(A cup B) = probability that A or B occurs
P(A) = probability of event A
P(B) = probability of event B
P(A cap B) = probability that both A and B occur
P(A) = probability of event A
P(B) = probability of event B
P(A cap B) = probability that both A and B occur
From the union formula, we can also derive conditional probabilities such as P(A|B) = P(A cap B) / P(B), which measures the chance of A given that B has occurred.
Parameters
Result
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Frequently Asked Questions
What is the formula for calculating the probability of two non-mutually exclusive events?
The formula is P(A ∪ B) = P(A) + P(B) – P(A ∩ B), where P(A ∪ B) is the probability of either event A or B occurring, P(A) and P(B) are the probabilities of events A and B respectively, and P(A ∩ B) is the probability of both events A and B occurring.
How do I use this calculator to find the probability of two events happening?
Enter the probabilities for each event and whether they are mutually exclusive or not. The calculator will then apply the inclusion-exclusion principle to give you the combined probability.
What does it mean if the result is 1?
A result of 1 means that either one or both events are certain to happen, as the maximum probability value is 1.
Can this calculator handle more than two events?
This specific calculator is designed for two events. For more complex scenarios involving multiple events, you may need a different tool or to manually apply the inclusion-exclusion principle step by step.
What if the events are mutually exclusive?
If the events are mutually exclusive, P(A ∩ B) = 0. The formula simplifies to P(A ∪ B) = P(A) + P(B).
How do I interpret a probability of 0?
A probability of 0 means that the event is impossible; it will not happen under any circumstances.
Can this calculator be used for dependent events?
This calculator assumes independent events. For dependent events, you would need to adjust the probabilities by considering the conditional dependencies between them.
Results are for informational purposes only and do not constitute professional advice.