Exam-style question
Try this first
For independent events A and B with P(A) = 0.5 and P(B) = 0.5, find P(A and B). Show your working one step at a time.
Model answer
What a good answer should say
- The final answer is 0.25.
- Use the multiplication rule because the events are independent.
- Multiply P(A) by P(B).
- 0.5 x 0.5 = 0.25.
This answer is tied to the objective: M1 Understand and use mutually exclusive and independent events when calculating probabilities; link to discrete and continuous distributions..
Explanation
Why this works
Use the explanation to connect the worked answer back to M1 Understand and use mutually exclusive and independent events when calculating probabilities; link to discrete and continuous distributions..
exam warm-up keeps the canonical answer 0.25 fixed before the model answer is written, so the worked solution and final answer agree.
Maths method check
- Topic focus: Statistics.
- Question style: exam_style.
- Reasoning demand: recall.
- Check the operation, notation, units, and final answer form against the question before moving on.
Common mistake
No common mistake is linked to this question yet.