Coverage & provenance · Arithmetic & geometric progressions
All coverage topics · Student practice
Indexing is not transcription, and transcription is not mathematical review. This page keeps those stages visible.
20 of 20 groups have authored prompts and authored interactive lessons; 0 await conversion. 20 have mathematical review recorded. Review includes documented qualifications where the printed source is inconsistent or depends on an unstated assumption. This is a first authoring and mathematical review pass, not independent expert certification. Difficulty ratings remain unassigned. The ledger below distinguishes these states.
Inventory reconciliation: Inequalities Q13–14 are on question PDF page 3, printed page 22. Their extra indentation caused the initial scan to stop at Q12. The corrected topic count is 14 and the overall count is 248; original source bytes are unchanged.
Collection-wide source ledger
248 complete-source articles and 15 topic metadata articles cover 468 original page instances. Source transcription, mathematical review and browser acceptance are recorded separately.
Download the native page-by-item ledger →Topic ledger
| Topic | Groups | Authored explanations | Maths review | Source pages |
|---|---|---|---|---|
| 12 · Arithmetic & geometric progressions | 20 | 20 / 20 | 20 / 20 | 8 question / 32 solution |
Source qualifications and cautions
The original pages remain unchanged. Corrections, interpretation choices and necessary domain conditions are recorded alongside the authored working.
12-02 · reviewed
The percentage statement implicitly concerns a nonzero positive total; a zero GP cannot have a strict error less than zero.
12-05 · reviewed
The printed solution divides by r^4 and thereby omits the zero-ratio GP. The displayed main answer follows its intended nondegenerate branch.
12-06 · reviewed
An infinite GP need not have a finite sum. The printed solution supplies a convergence assumption absent from part (b) wording.
12-09 · reviewed
The source excludes a=1 but omits the necessary a≠0 restriction; its convergence answer also omits the zero-series endpoint a=2.
12-12 · reviewed
A zero-length twenty-first piece is not a ribbon piece; convert metres to centimetres before combining totals.
12-13 · reviewed
Lap totals establish a lead change between laps 3 and 4. The precise within-lap crossing time needs a speed model; the source gives only lap durations.
12-15 · reviewed
Round a numerical threshold only after imposing k divides 500; an arbitrary integer such as 22 is not allowed.
12-16 · reviewed
The model specifies synchronised endpoints. Within-hop motion is unspecified; the distance calculation follows the source endpoint/constant-progress model. A strict real lower bound has an infimum rather than an attained minimum.
12-17 · reviewed
A month-end formula alone can give the right month but the wrong day; check the deposit at the start of that month.
12-20 · reviewed
Nine increases reach session 10; sixty further increases reach session 70. Rounded lower bounds are approximate and should not replace the exact inequality in calculations.
Series expansion topic 09 has byte-identical question and solution PDFs. Their printed solutions are transcribed once; the provenance ledger accounts for both file instances.
Exam references
2025 TJC H2 Maths (9758), JC2 MSM. Individual exam references are retained on question pages; original question and solution page numbers are kept independently. Source margin notes, short keys, tables and diagrams are transcribed into native articles. All 468 original page instances map to 2,703 native item records. Diagrams are source-specific D3 SVGs.
Owner reports that the source contributor has permission to republish. Original attribution and source-page provenance are retained. Originals are preserved privately for quality checks and are excluded from the delivered site.
Byte verification
Original ZIP: 11,692,621 bytes.
SHA-256: 39645f7e5aee1f8d870eca9267920157747d43725a1cc8b0486cb43ca532b1cc
30 PDFs / 468 PDF pages. Every PDF has its own byte length and SHA-256 in the manifest.
Question-by-question status
| Question | Conversion | Mathematical review | Question PDF pages |
|---|---|---|---|
| 12-01 · Source review | authored | reviewed | 1 |
| 12-02 · Source review | authored | reviewed | 1 |
| 12-03 · Source review | authored | reviewed | 1 |
| 12-04 · Source review | authored | reviewed | 1 |
| 12-05 · Source review | authored | reviewed | 1 |
| 12-06 · Source review | authored | reviewed | 2 |
| 12-07 · Source review | authored | reviewed | 2 |
| 12-08 · Source review | authored | reviewed | 2 |
| 12-09 · Source review | authored | reviewed | 3 |
| 12-10 · Source review | authored | reviewed | 3 |
| 12-11 · Source review | authored | reviewed | 3 |
| 12-12 · Source review | authored | reviewed | 4 |
| 12-13 · Source review | authored | reviewed | 4 |
| 12-14 · Source review | authored | reviewed | 4 |
| 12-15 · Source review | authored | reviewed | 5 |
| 12-16 · Source review | authored | reviewed | 5 |
| 12-17 · Source review | authored | reviewed | 5, 6 |
| 12-18 · Source review | authored | reviewed | 6 |
| 12-19 · Source review | authored | reviewed | 6 |
| 12-20 · Source review | authored | reviewed | 7 |