Lesson 2.03b

2.03b Probability diagrams and tree diagrams Quiz: OCR Maths, Unit 13

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

In partnership with Revision Ninja

Lesson 2.03b, Probability diagrams and tree diagrams: 20 multiple choice questions for the OCR Maths (H240), Unit 13: Probability, written with Revision Ninja.

Host it live on the board and students join with a game code on their own devices, or revise alone with Free Play. The answers are revealed in the game.

Host this setFree Play

The 20 questions

  1. What set notation represents the event where both event A and event B occur?

    • A ∢ B
    • A'
    • A ∩ B
    • A | B

  2. Which set notation represents the complement of event A occurring?

    • A | B
    • A'
    • A ∩ B
    • A ∢ B

  3. What notation represents the conditional probability of event A given event B occurs?

    • P(A ∢ B)
    • P(B | A)
    • P(A | B)
    • P(A ∩ B)

  4. What is the sum of probabilities on branches originating from the same node on a tree diagram?

    • 0
    • 2
    • 1
    • 0.5

  5. Which expression represents the addition rule for the probability of A or B, P(A ∢ B)?

    • P(A) + P(B) + P(A ∩ B)
    • P(A) + P(B)
    • P(A) × P(B)
    • P(A) + P(B) - P(A ∩ B)

  6. Which formula correctly defines the conditional probability P(A | B)?

    • P(A) × P(B)
    • P(A ∩ B) / P(A)
    • P(A ∢ B) / P(B)
    • P(A ∩ B) / P(B)

  7. In set notation, which expression represents the event that A occurs but B does not?

    • A ∩ B'
    • (A ∩ B)'
    • A ∢ B'
    • A' ∩ B

  8. If P(A) = 0.4, P(B) = 0.5, and P(A ∩ B) = 0.2, what is P(A ∢ B)?

    • 0.7
    • 0.2
    • 0.9
    • 0.3

  9. If P(A ∩ B) = 0.12 and P(B) = 0.4, what is P(A | B)?

    • 0.16
    • 0.48
    • 0.3
    • 0.28

  10. If the probability of event A occurring is 0.6, what is P(A')?

    • 0.6
    • 1.6
    • -0.6
    • 0.4

  11. Along a tree diagram path, successive branch probabilities are 0.3 and 0.4. What is the path probability?

    • 0.34
    • 0.12
    • 0.1
    • 0.7

  12. Out of 100 students, 60 study Maths, 40 study Physics, and 20 study both. How many study neither?

    • 20
    • 40
    • 10
    • 0

  13. In a survey of 50 adults, 15 are smokers. What is the probability a chosen adult is a non-smoker?

    • 0.35
    • 0.7
    • 0.15
    • 0.3

  14. If P(B | A) = 0.5 and P(A) = 0.6, what is P(A ∩ B)?

    • 0.3
    • 0.83
    • 0.1
    • 1.1

  15. If events A and B are mutually exclusive, with P(A) = 0.3 and P(B) = 0.4, what is P(A ∩ B)?

    • 0.1
    • 0.12
    • 0
    • 0.7

  16. Given P(A) = 0.7, P(B) = 0.5, and P(A ∢ B) = 0.9, what is P(A | B)?

    • 0.2
    • 0.6
    • 0.43
    • 0.3

  17. A bag contains 3 red and 2 blue balls. Two are picked without replacement. What is P(both red)?

    • 0.36
    • 0.3
    • 0.6
    • 0.24

  18. Given P(A') = 0.4, P(B) = 0.5, and P(A ∩ B) = 0.2, what is P(A' ∩ B')?

    • 0.2
    • 0.3
    • 0.1
    • 0.4

  19. If P((A ∢ B)') = 0.2, what is the probability of event A or event B occurring, P(A ∢ B)?

    • 0.5
    • 0.8
    • 0.7
    • 0.3

  20. If events A and B are independent, what is P(A | B) equal to?

    • P(A)
    • P(B)
    • P(A ∩ B)
    • 0

All OCR Maths quizzes