Math 9 · Unit 12: Probability · Cambridge Lower Secondary Maths Stage 9

Questions

1. 1. You roll a red fair dice and a blue fair dice. Are getting an even number on the red dice and getting an odd number on the blue dice independent events?

   • Yes
   • No
   Check

2. 2. You roll a red fair dice and a blue fair dice. Are getting an even number on the red dice and getting an even number on the blue dice independent events?

   • Yes
   • No
   Check

3. 3. You roll a red fair dice and a blue fair dice. Are getting an even number on the red dice and getting an odd number on the red dice independent events?

   • Yes
   • No
   Check

4. 4. Could the events 'There is a thunderstorm' and 'Zara is late for school' be not independent?

   • Yes
   • No
   Check

5. 5. Arun is late for school on Monday. Arun is late for school on Tuesday. Are these two events independent?

   • Yes
   • No
   Check

6. 6. There are 8 balls in a bag. Four are white and numbered 1 to 4; four are black and numbered 1 to 4. A ball is chosen at random. Find the probability that the ball is (i) white and 4, (ii) white, (iii) 4.

   • i 1/2, ii 1/4, iii 1/8
   • i 1/8, ii 1/2, iii 1/4
   • i 1/8, ii 1/4, iii 1/2
   • i 1/4, ii 1/2, iii 1/8
   Check

7. 7. There are 8 balls in a bag. Four are white and numbered 1 to 4; four are black and numbered 1 to 4. A ball is chosen at random. The ball is white. What is the probability that it is 4?

   • 1/4
   • 4/8
   • 1/8
   • 1/2
   Check

8. 8. There are 8 balls in a bag. Four are white and numbered 1 to 4; four are black and numbered 1 to 4. A ball is chosen at random. The ball is black. What is the probability that it is 4?

   • 1/8
   • 0
   • 1/4
   • 1/2
   Check

9. 9. There are 8 balls in a bag. Four are white and numbered 1 to 4; four are black and numbered 1 to 4. A ball is chosen at random. Event R is 'the ball is white'. Event F is 'the ball is 4'. Are R and F independent events?

   • Yes
   • No
   Check

10. 10. You roll a fair dice. What is the probability that the number you get is (i) less than 4, (ii) more than 2, (iii) a multiple of 3?

    • i 1/2, ii 2/3, iii 1/3
    • i 2/3, ii 1/2, iii 1/2
    • i 1/2, ii 1/3, iii 2/3
    • i 1/3, ii 1/2, iii 1/6
    Check

11. 11. You roll a fair dice and get an even number. What is the probability that the number is (i) less than 4, (ii) more than 2, (iii) a multiple of 3?

    • i 1/3, ii 1/3, iii 2/3
    • i 1/3, ii 2/3, iii 1/3
    • i 2/3, ii 1/3, iii 1/6
    • i 1/2, ii 1/2, iii 1/2
    Check

12. 12. You roll a fair dice. Are getting an even number and getting a multiple of 3 independent events?

    • Yes
    • No
    Check

13. 13. You roll a fair dice three times and get 2 each time. What is the probability of a 2 next time?

    • 1/6
    • more than 1/6
    • 0
    • less than 1/6
    Check

14. 14. The names of 3 boys and 3 girls are put in a hat. One name is chosen at random and not replaced. Then a second name is chosen at random. Event A is 'the first person is a girl'. Event B is 'the second person is a girl'. Are A and B independent events?

    • Yes
    • No
    Check

15. 15. The names of 3 boys and 3 girls are put in a hat. One name is chosen at random and not replaced. Then a second name is chosen at random. Event A is 'the first person is a girl'. Event B is 'the second person is a girl'. Suppose the first name is replaced before the second name is taken. Are the events independent this time?

    • Yes
    • No
    Check

16. 16. Cards A to H. The letter is in FACE. What is the probability it is also in BACH?

    • 1/8
    • 1/4
    • 3/4
    • 1/2
    Check

17. 17. Cards A to H. The letter is NOT in FACE. What is the probability it is in BACH?

    • 1/8
    • 3/4
    • 1/4
    • 1/2
    Check

18. 18. In a bag there are 8 cards with the letters A, B, C, D, E, F, G and H. One card is chosen at random. Are being in the word FACE and being in the word BACH independent events?

    • Yes
    • No
    Check

19. 19. In a bag there are 8 cards with the letters A, B, C, D, E, F, G and H. One card is chosen at random. Are being in the word FACE and being in the word EACH independent events?

    • Yes
    • No
    Check

20. 20. A black fair dice and a white fair dice are rolled. Are X and Y independent events?

    • Yes
    • No
    Check