A worked modelling mistake worth logging
Original illustrative Mathematics AA-style question, not a past IB examination question or official markscheme. A population model is P(t) = 450e^(0.06t), with t measured in years. When does the model first predict double the initial population?
Incorrect reasoning: 450(1 + 0.06t) = 900 gives t = 16.67 years. This incorrectly treats the given exponential model as linear growth. The number is plausible but answers a different model.
Correct equation: 450e^(0.06t) = 900, so e^(0.06t) = 2. Taking natural logarithms yields t = ln(2)/0.06 ≈ 11.55 years.
Error category: MODEL_SUBSTITUTION, rather than a simple logarithm slip. The missing habit is checking that your solving method preserves the model named in the question.
Independent retest: If P(t) = 500e^(0.04t), doubling requires t = ln(2)/0.04 ≈ 17.33 years. Close the worked answer before attempting the new rate.
Use this error-category approach when marking a legally accessible subject-, paper- and session-matching practice question. This page does not reproduce or claim to grade any official paper.
Which subjects actually have free official samples?
Filter the papers described in the IB's public collection, including their stated first-assessment versions. This is an index of selected samples, not a pirate archive or a complete IB paper library. Follow the source link to access the files and check changes.
8 matching sample categories · official source checked 9 October 2026
English A: literature
Past examination
Paper 1 and marking notes
First assessment 2021
English A: literature
Past examination
Paper 2
Verify version on IB page
English B
Specimen
HL/SL paper 2 audio; specimen papers and markschemes
First assessment 2020
Geography
Specimen
Specimen papers and markschemes
First examinations 2019
History
Specimen
Papers 1 and 2; HL paper 3 with markschemes
First examinations 2017
Digital society
Specimen
Digital Society specimen pack
First assessment 2024
Mathematics AA
Specimen
Analysis & Approaches specimen pack
Check current assessment spec
Mathematics AI
Specimen
Applications & Interpretation specimen pack
Check current assessment spec
Past paper or specimen paper?
A past paper comes from an actual examination. A specimen paper illustrates a paper format for a course, often before students have sat the first exam for that syllabus. Both can be useful—but neither is a reliable forecast of your question topics.
The IB's publicly accessible library currently lists samples for English A, English B, Geography, History, mathematics and selected other courses. Availability differs across subjects. If a paper is missing, ask your teacher or coordinator what your school is licensed to use.
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01Exam session
Paper matches your current course's assessment specification.
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02Subject and level
You have the exact subject, HL/SL and paper component.
Avoid: A specimen for another course or level is used as exam prediction.
03Markscheme
Use an official markscheme or marking notes when publicly provided.
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04Legitimate access
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Turn one paper into a diagnostic
Do the questions under realistic conditions first. After marking, sort every lost mark into one of these four labels instead of calculating only a final score: knowledge gap (the concept was missing), application gap (you knew it but could not use it), command-term error (you answered a different task), and time pressure (you ran out of time). Pick the highest-impact repeat error for your next practice block.
This is an original study-log method, not an IB rule or an official examiner classification. The revision planner turns it into a retest schedule.
Questions that change the next step
Are official IB past papers free to download?
The IB makes selected real past and specimen papers freely available on its sample-paper page, but the collection is not exhaustive. Your school may have licensed access to further materials. A freely accessible file is not automatically licensed for redistribution.
Will an old IB exam paper match my next exam?
Not necessarily. Check your subject, level, paper number and first-assessment version. When a syllabus has changed, use the old paper for the relevant skills only; do not infer that its format or marks will carry forward.
Should I memorize the paper markscheme?
Use the official markscheme to diagnose why your answer missed marks, then close it and answer an equivalent question independently. A repeated error tells you more about the next revision task than memorizing a particular model answer.
Sources and verification
Primary-source references for this article, checked 8 October 2026. Rules and admission policies can change; confirm the current version for your assessment session or university course.
- IB — official sample exam papers ↗
Selected real past and specimen papers published openly by the IB; checked October 2026.
- IB — DP assessment and examinations ↗
Official assessment framework and resources context.
Independent student guidance, not an official IB publication. Ask your school coordinator to confirm policies relevant to your circumstances.