Common Core · High school
HSS-CP.A.2
High school — Understand that two events are independent when the probability of both occurring together is the product of their probabilities.
High school — Understand independence, and that the probability of two independent events both occurring is the product of their probabilities.
The 2 skills that cover it
- Complements, Or & AndCombine probabilities: the complement rule for "not", the addition rule for "or", and the multiplication rule for independent events.Read the lesson →
- Compound EventsWork out probabilities for experiments with more than one stage, and keep track of whether the first stage changes the second.Read the lesson →
What a student should be able to do
- Use P(not A) = 1 - P(A) to find the probability of a complement.
- Add probabilities for events that cannot both happen, and subtract the overlap when they can.
- Multiply probabilities for independent events joined by "and".
- Answer an "at least one" question by working with the complement instead.
- Find the probability of a two-stage event with replacement.
- Adjust both the numerator and the denominator when there is no replacement.
- Read a probability off an organised list or a two-way table of a sample space.
- Handle an "at least one" compound event through its complement.