HS.S-CP.3
Understand that the conditional probability of an event A given B is the probability that event A will occur given the knowledge that event B has already occurred. Apply the formula P(A given B) = P(A and B)/P(B) given a conditional probability situation.
Example Problems
Five fair six‑sided dice are rolled simultaneously.
What is the probability that exactly two of the dice show a ?
What is the probability that exactly two of the dice show a ?
Eight friends sit randomly in a straight row of 8 seats.
What is the probability that Charlie and Dana sit next to each other (in either order)?
What is the probability that Charlie and Dana sit next to each other (in either order)?
Seven friends take random seats in a straight row of 7 chairs.
What is the probability that Alice sits in one end seat and Bob sits in the other end seat?
What is the probability that Alice sits in one end seat and Bob sits in the other end seat?
Khan Academy ResourcesConditional probability and independenceConditional probability using two-way tablesTree diagrams and conditional probabilityCalculate conditional probabilityConditional probability with Bayes' TheoremConditional probability and independenceGeneral multiplication rule example: independent eventsConditional probability tree diagram example
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