Compound Events

Independent and dependent events

Learning Objectives
Discussion Starters
Differentiation Ideas
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lessons (3)

Compound probability deals with multiple events occurring together or in sequence. Understanding AND (intersection) and OR (union) probabilities, along with the distinction between independent and dependent events, is essential for complex probability problems.

What Students Will Learn

  • Calculate P(A and B) for independent events
  • Calculate P(A or B) for any events
  • Distinguish independent and dependent events
  • Use multiplication and addition rules
  • Solve multi-step probability problems

Frequently Asked Questions

What is the difference between AND and OR in probability?

AND (intersection): both events happen - multiply probabilities for independent events. OR (union): at least one happens - add probabilities and subtract overlap.

What makes events independent?

Events are independent if one occurring does not affect the other's probability. Coin flips are independent; drawing cards without replacement is dependent.

What is the addition rule?

P(A or B) = P(A) + P(B) - P(A and B). Subtract the overlap to avoid counting it twice.