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Flip to reveal answersHow do you find the probability of an event with equally likely outcomes?
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All 9 Flashcards — Basic probability
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Question
How do you find the probability of an event with equally likely outcomes?
Answer
Favourable outcomes ÷ total outcomes: P(A) = n(A)/n(U).
Question
What range must a probability lie in?
Answer
Between 0 and 1 inclusive.
Question
What is the complement rule?
Answer
P(A′) = 1 − P(A).
Question
How do you find P(at least one)?
Answer
Use the complement: 1 − P(none).
Question
How many outcomes are in the sample space for two dice?
Answer
36 (6 × 6 ordered outcomes).
Question
In a sample-space grid, do (2,5) and (5,2) count separately?
Answer
Yes — they are different ordered outcomes.
Question
How do you find the probability of a sequence of events?
Answer
Multiply the probabilities along the chain.
Question
What changes for 'without replacement'?
Answer
After each draw the totals reduce — one fewer item and one fewer of the drawn type.
Question
With replacement vs without — what's the difference?
Answer
With replacement the probabilities stay the same each draw; without, they change.
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Topic 4.5 hub
Probability basics
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