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: M2 Understand and use conditional probability, including tree diagrams, Venn diagrams and two-way tables; understand and use the conditional probability formula P(A|B) = P(A intersection B) / P(B)..
Explanation
Why this works
Use the explanation to connect the worked answer back to M2 Understand and use conditional probability, including tree diagrams, Venn diagrams and two-way tables; understand and use the conditional probability formula P(A|B) = P(A intersection B) / P(B)..
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.