Probability mixed checkpoint
Sample probability skills and choose your next review.
What you will learn
- Choose the requirements for your exam tier.
- Explain each method before choosing an answer.
- Follow a missed skill to its teaching lesson.
Check your reasoning across the pathway
Core has 5 questions; Extended has 7, including any Extended-only requirements. Work on paper before selecting an answer, then read the feedback. Changing tier starts a fresh attempt. The questions sample taught skills rather than represent the full range of exam questions.
Some questions revisit a lesson's pause check so you can retrieve the method in a mixed sequence. A remembered option alone is weak evidence: explain the reasoning and try the independent or transfer practice without revealing help. Drawings, constructions and written solutions are self-checked; these are not automatically marked exam responses.
Use a missed skill to plan a return
The review plan records first-attempt choices for this session and links the skills you missed to their lessons. Choose one useful review, close the worked answer and solve again from a blank page. Use that lesson's saved review choice to plan a later visit.
This practice check is not saved as an exam grade and does not mark lessons complete. Correct answers to this small sample do not establish mastery.
Probability checkpoint
Changing tier starts a fresh attempt. This practice check is not saved as a grade or used to mark lessons complete.
Question 1 of 5 · Core and Extended
P(rain) = 0.35. Find P(no rain).
Worked example
Three red and two blue are drawn twice without replacement. Find probability of at least one red.
Show the worked solution
- The complement is two blue.
- P(BB) = (2/5)(1/4) = 1/10.
- Subtract from one to obtain 9/10.
Answer 9/10.
Common mistakes
- Selecting a remembered option without explaining the method.
- Treating a sampled checkpoint as a full exam or saved grade.
What can you explain now?
What should you do after missing a skill in this check?
Compare with the explanation
Revisit its lesson and solve a fresh written problem without the answer visible.
Use the explanation to repair the method, then test retrieval rather than repeating a memorised answer.
After trying it yourself, choose your next review. This is your self-assessment.
Your review choice appears on Today. Sign in to sync it across devices.