Sec 3 and Sec 4 · 48 papers
O-Level Combined Science prelim papers, free with answers
48 Combined Science papers set by 30 Singapore secondary schools between 2019 and 2024: 17 Combined Physics, 17 Combined Chemistry and 14 Combined Biology. 26 are Sec 4 prelim exams, and 46 come with answers. They prepare for O-Level Science (5086, 5087, 5088) in 2026 and SEC G3 Science (K326, K327, K328) from 2027.
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Combined Physics papers
Sec 4 Prelim exams 9
Maris Stella High Paper 1
Ngee Ann Paper 1
Serangoon Paper 1
Unity Paper 1
Sec 3 End-of-year exams 8
Seng Kang
Admiralty
Bedok View
Damai
Meridian
Orchid Park
PeirceCombined Chemistry papers
Sec 4 Prelim exams 9
Bedok Green
Broadrick
Christ Church
Compassvale
Chua Chu KangSec 3 End-of-year exams 8
Deyi
Springfield
Bedok South
Pasir RisCombined Biology papers
Sec 4 Prelim exams 8
Mayflower Paper 1
Kuo Chuan Presbyterian Paper 1
Paya Lebar Methodist Girls' Paper 1
Queenstown Paper 4
Sec 3 End-of-year exams 6
Geylang Methodist
St Anthony's Canossian
West Spring
Pasir Ris CrestThe Combined Science exam these papers prepare for
The papers were set for O-Level Science (5086, 5087, 5088) in 2026 and SEC G3 Science (K326, K327, K328) from 2027. The 2027 papers are:
| Paper | Type | Time | Marks | Weighting |
|---|---|---|---|---|
| Paper 1 | Multiple choice, 40 questions on both sciences | 1 h | 40 | 20% |
| Paper 2 | Structured and free response, Physics | 1 h 15 min | 65 | 32.5% |
| Paper 3 | Structured and free response, Chemistry | 1 h 15 min | 65 | 32.5% |
| Paper 4 | Structured and free response, Biology | 1 h 15 min | 65 | 32.5% |
| Paper 5 | Practical test | 1 h 30 min | 30 | 15% |
A candidate sits Paper 1, Paper 5 and the two of Papers 2, 3 and 4 that match the combination: K326 is Physics and Chemistry, K327 is Physics and Biology, K328 is Chemistry and Biology. School prelims often split the multiple-choice paper by science, so their marks differ from the table.
Source: SEAB, SEC G3 Science K326, K327 and K328 (2027).
Which topics do these papers test most?
Counted from the topics listed on each paper's page: how many papers test each topic. A topic that shows up in most papers is worth revising first.
Combined Physics
| Topic | Papers |
|---|---|
| Thermal physics | 15 of 17 |
| Kinematics | 14 of 17 |
| Dynamics | 14 of 17 |
| Energy, work and power | 14 of 17 |
| Pressure | 13 of 17 |
| Measurement, mass and density | 12 of 17 |
| Turning effect of forces | 11 of 17 |
| Light | 11 of 17 |
Combined Chemistry
| Topic | Papers |
|---|---|
| Experimental chemistry and separation | 17 of 17 |
| Atomic structure | 17 of 17 |
| Chemical bonding and structure | 17 of 17 |
| Acids, bases and salts | 17 of 17 |
| The Periodic Table | 16 of 17 |
| Mole concept | 15 of 17 |
| Metals and the reactivity series | 11 of 17 |
| Salts | 11 of 17 |
Combined Biology
| Topic | Papers |
|---|---|
| Biological molecules and enzymes | 14 of 14 |
| Transport in humans | 14 of 14 |
| Nutrition in plants | 13 of 14 |
| Nutrition in humans | 12 of 14 |
| Movement of substances | 12 of 14 |
| Transport in flowering plants | 11 of 14 |
| Cell structure and organisation | 10 of 14 |
| Respiration | 10 of 14 |
Linked topics have a free study guide with a worked example and practice questions.
How to use Combined Science papers well
- Split revision by scienceEach science has its own 65-mark paper, so a weak science shows up clearly. Mark each part separately.
- Do the MCQ paper as one setPaper 1 mixes both sciences in 40 questions in an hour, so practise switching between them.
- Do not skip the practicalThe practical test is 15% of the grade, and every school paper here shows the style of question it asks.
Questions about these papers
Are these Combined Science papers still good practice for the 2027 SEC?
Yes. The final O-Level is in October and November 2026, and from 2027 Sec 4 students sit the Singapore-Cambridge Secondary Education Certificate (SEC). School papers set for the O-Level test the same subject content, though the marks of a school paper can differ from the 2027 papers in the table above. Check any topic you are unsure of against the current syllabus.
Do the Combined Science papers come with answers?
46 of the 48 come with answers, as a separate PDF so the paper can be tried first. 45 of those are the school's own answer key, and the rest were typed by an unofficial source, which the paper's page says because we have not checked them. Unity 2024 Sec 4 Paper 1 and Unity 2024 Sec 4 Paper 2 have no answers yet.
Is Combined Science easier than the pure sciences?
It covers less. Each science in Combined Science takes a part of the pure syllabus, and its written paper is 65 marks instead of the pure paper's 80. Both are graded on the same G3 scale from A1 to 9.
Are the papers free?
Yes. Enter your email and mobile once, and every paper on this site then downloads straight away on that device.