What is this calculator?
Combine the probabilities of two independent events.
What can you use it for?
Use it when solving an exercise, checking a result, or working with the particular quantities shown in this form. Combine the probabilities of two independent events.
How to use it
- Enter p(a), from 0 to 1.
- Enter p(b), from 0 to 1.
- Select Calculate (or Generate for random tools).
- Read the answer and any additional results below the form. Check the units and the limits of the method.
Formula and method
Both events = p(a), from 0 to 1 × p(b), from 0 to 1
At least one event = p(a), from 0 to 1+p(b), from 0 to 1-p(a), from 0 to 1 × p(b), from 0 to 1
Neither event = (1-p(a), from 0 to 1) × (1-p(b), from 0 to 1)
At least one event = p(a), from 0 to 1+p(b), from 0 to 1-p(a), from 0 to 1 × p(b), from 0 to 1
Neither event = (1-p(a), from 0 to 1) × (1-p(b), from 0 to 1)
The formula uses the units and definitions shown above. Each input is substituted before the arithmetic is evaluated; the calculated output is rounded for display.
Worked example
P(A), from 0 to 1: 0.5, P(B), from 0 to 1: 0.3. The result is 0.15 (both events).
Assumptions and limits
Events must be independent.
Frequently asked questions
What inputs does the Probability Calculator need?
Use p(a), from 0 to 1, p(b), from 0 to 1. Read the answer and any additional results below the form. Check the units and the limits of the method.
What assumptions apply to the Probability Calculator?
Events must be independent.