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S1 Maths: Ratio and Proportion (Paper 1 (basics))
S1 Maths: Ratio and Proportion (Paper 1 (basics))
Paper 1 (basics): ten questions on ratio and proportion with answers and one-line notes.
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: S1 Maths: Ratio and Proportion |
| Level | S1 |
02 Questions (10 items)
- FoundationSimplify the ratio 12 : 18.
- FoundationA class has 15 boys and 20 girls. Find the ratio of boys to girls in simplest form.
- FoundationDivide 24 sweets between A and B in the ratio 3 : 5. How many does each get?
- IntermediateGiven 3 : 5 = ? : 20, find the missing term.
- IntermediateSquash and water are mixed in the ratio 1 : 4. If 800 mL of water is used, how much squash is needed?
- IntermediateA car travels at 60 km/h for 3 hours. How far does it go?
- ChallengeFive identical buns cost $45. At the same unit price, what do 7 cost?
- ChallengeA map has a scale of 1 : 200. What real length does 5 cm on the map represent, in cm and in m?
- ChallengeTwo numbers are in the ratio 4 : 7. What fraction of the second number is the first?
- Error redoError clinic: a student wrote 2 : 3 = 4 : 5. Is that correct? Use cross-multiplication.
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 12 : 18 = 2 : 3. | Divide both terms by the highest common factor 6. |
| 2 | Boys : girls = 3 : 4. | The highest common factor of 15 and 20 is 5, so divide both by 5. |
| 3 | A gets 9 and B gets 15. | There are 3 + 5 = 8 parts, so each part is 3 sweets. |
| 4 | The missing term is 12. | The second term is multiplied by 4, so multiply the first term by 4 too. |
| 5 | 200 mL of squash is needed. | The water is 4 parts of 800 mL, so one part is 200 mL. |
| 6 | It travels 180 km. | Distance equals speed multiplied by time. |
| 7 | Seven buns cost $63. | Find the unit price first, then multiply by 7. |
| 8 | It represents 1000 cm, which is 10 m. | Each centimetre on the map stands for 200 cm in real life. |
| 9 | The first number is 4/7 of the second. | A ratio a : b means a divided by b. |
| 10 | No: 2 x 5 = 10 but 3 x 4 = 12, so the two ratios are not equal. | Two ratios are equal only when the cross products match. |
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.
In ratio questions the first step is always to make the parts match: divide by the highest common factor, or make the middle term of a linked ratio the same. To divide a quantity in a ratio, find the total number of parts, then the value of one part, then multiply back. A map scale is given in centimetres, so convert units before scaling. Rates such as speed and unit price are ratios of two quantities, and an average speed uses total distance over total time. Worker-days and speed-time pairs are inverse relations, so invert the ratio.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.
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