# Complementary events

Understand and apply the rule that probabilities of all mutually exclusive outcomes sum to one; use this to find the probability of a complementary event (P(not A) = 1 − P(A))

Builds on: Probabilities Sum to One (hard, https://ai.page/c/probabilities-sum-to-one/en.md), The Probability Scale (hard, https://ai.page/c/the-probability-scale/en.md)

Concept id: complementary-events. Subject: maths. Licence: CC BY-SA 4.0.

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