Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
Independent events are two or more events where the occurrence of one event does not affect the probability of the other events occurring. Mathematically, events A and B are independent if $P(A \cap B) = P(A) \cdot P(B)$.
5 Must Know Facts For Your Next Test
For two independent events A and B, $P(A|B) = P(A)$ and $P(B|A) = P(B)$.
The independence of two events implies that knowing the outcome of one provides no information about the other.
If events A and B are independent, then their complements (A' and B') are also independent.
In a sequence of trials, like flipping a fair coin multiple times, each flip is an independent event.
Independence is different from mutual exclusivity; mutually exclusive events cannot happen simultaneously, whereas independent events can.