The probability that a bus is late is and the probability that it is early is . What is the probability that it is either late or early?
Answer and explanation
Correct answer: A. 0.75
- Step 1: The events cannot happen together, so add the probabilities.
- Step 2: .
Answer
0.75.
Why not the others: 0.135: This multiplies the probabilities, which is used for independent events happening together. 0.25: This is the probability that the bus is on time. 0.15: This subtracts the probabilities.
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