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Primary Maths: Chance and Probability Basics (Paper 3 (challenge))
Primary Maths: Chance and Probability Basics (Paper 3 (challenge))
This paper adds two step and independent events: multiplying probabilities, changing the denominator without replacement, and comparing spinners.
Direct answers For two draws, write the first probability, adjust the counts, write the second, then multiply and simplify.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: Primary Maths: Chance and Probability Basics |
| Level | P6 |
02 Questions (10 items)
- FoundationA bag holds 4 red and 6 blue balls. What is the probability of red in simplest form?
- FoundationA fair dice is thrown once. What is the probability of a prime score?
- FoundationTwo fair coins are tossed. What is the probability of at least one head?
- IntermediateA bag starts with 6 red and 4 blue balls and 4 more red balls are added. What is the probability of red now?
- IntermediateA fair dice is thrown 90 times. How many odd scores are expected?
- IntermediateA bag has 20 balls and the probability of red is 1/4. How many red balls are there?
- ChallengeSpinner A has 4 equal parts with 2 red; spinner B has 8 equal parts with 3 red. Which is more likely to land on red?
- ChallengeA fair dice is thrown twice. What is the probability of a 6 both times?
- ChallengeA bag holds 5 red and 5 blue balls. A red ball is drawn and not replaced. What is the probability the second is red too?
- Error redoA student says the probability of a 7 on one dice is 1/6 because every score has 1/6. What is correct?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 2/5 | There are 10 balls and 4 are red, so 4/10 simplifies to 2/5. |
| 2 | 1/2 | The primes from 1 to 6 are 2, 3 and 5, so 3 out of 6 simplifies to 1/2. |
| 3 | 3/4 | Of the four results only tail tail fails, so the other three all have at least one head. |
| 4 | 5/7 | The red balls become 10 and the total becomes 14, so 10/14 simplifies to 5/7. |
| 5 | 45 times | The odd scores 1, 3 and 5 give probability 1/2, and half of 90 is 45. |
| 6 | 5 | The count is the total times the probability, and a quarter of 20 is 5. |
| 7 | Spinner A | A gives 2/4, that is 1/2, and B gives 3/8, so A is more likely. |
| 8 | 1/36 | The two throws are independent, so multiply: one sixth times one sixth is 1/36. |
| 9 | 2/9 | The first is 5/10 and then 4 of the 9 remaining are red, giving 20/90, which is 2/9. |
| 10 | 0 | A dice only shows 1 to 6, so a 7 is impossible and the probability is 0. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Three steps: count every possible outcome, count the outcomes that fit, then divide and simplify; a probability always lies between zero and one.Tutor Registration →
Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.