# WDM11/01 January 2020

> WDM11/01 January 2020: 7 questions, 75 marks. Difficulty 0.45, deviation 0.16, algebraic 0.26, text density 0.27. Edexcel IAL Mathematics D1.

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Edexcel IAL · Mathematics · 2020 January

This Decision Mathematics 1 (WDM11) paper contains 7 questions worth 75 marks. The profile below reports five mark-weighted difficulty and complexity measures, and every question row repeats them. Full question text and mark scheme open in the Interactive Practice Hub.

- Edexcel IAL
- D1
- 7 questions
- 75 marks
- Free paper
- [Practise this paper](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9)
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Core finding

**WDM11/01 January 2020 is a past paper for Edexcel IAL Decision Mathematics 1 (WDM11), with 7 questions worth 75 marks.** Its mark-weighted Difficulty Measure is 0.45 on a 0.20–0.75 scale, with a Difficulty Deviation of 0.16 and a mark split of 17.3% Easy, 62.7% Medium and 20.0% Hard. Algebraic complexity averages 0.26; text density and modelling average 0.27. All five measures use 27 part-level tags, not candidate results. Every question row below repeats them and opens the Interactive Practice Hub for that question.

## Difficulty & complexity profile

All five measures are mark-weighted and calculated from 27 parts carrying 75 part marks. Difficulty tags cover 27 parts, algebraic tags 27 and text-density tags 27. Tags are internal metadata, not official exam-board ratings.

- **Difficulty Measure**: 0.45 — 0.20–0.75 · nearer Medium
- **Difficulty Deviation**: 0.16 — 0 = uniform; higher = more mixed
- **Difficulty Ratio**: 17.3 / 62.7 / 20.0 — % Easy / Medium / Hard
- **Algebraic Complexity Measure**: 0.26 — 0.20–0.75 · nearer Low
- **Text Density and Modelling Measure**: 0.27 — 0.20–0.75 · nearer Low

Scale: Easy 0.20 · Medium 0.45 · Hard 0.75, and Low 0.20 · Medium 0.45 · High 0.75 for the two complexity measures. [How each band is defined and how the values are calculated →](https://www.examsci.com/guides/difficulty-and-complexity-measures/)

### Definitions and calculation

| Measure | Paper value | Formula |
| --- | --- | --- |
| **Difficulty Measure** | 0.45 | Σ(d_i × w_i) / Σw_i, with d = 0.20 / 0.45 / 0.75 |
| **Difficulty Deviation** | 0.16 | √(Σw_i(d_i − μ)^2 / Σw_i) |
| **Difficulty Ratio** | 17.3% Easy / 62.7% Medium / 20.0% Hard | marks in band / all tagged marks |
| **Algebraic Complexity Measure** | 0.26 | Σ(c_i × marks_i) / Σmarks_i, with c = 0.20 / 0.45 / 0.75 |
| **Text Density and Modelling Measure** | 0.27 | Σ(t_i × marks_i) / Σmarks_i, with t = 0.20 / 0.45 / 0.75 |

w_i equals the part marks, except for a Hard part worth 4 or more marks, where w_i = marks^0.75 to offset the accessible starter steps inside long structured questions.

## Question list

Each measure is recalculated from the parts of that question and uses the same weights as the paper profile.

| Question | Topic | Marks | Difficulty Measure | Algebraic Complexity Measure | Text Density and Modelling Measure | Practice |
| --- | --- | --- | --- | --- | --- | --- |
| **Q1** FRQ | [3. Algorithms on graphs II](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms-on-graphs-ii/) | 5 | 0.45 Medium | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=1a788c72-4f70-432a-9397-d7b1a346ad52&source_detail=WDM11%2F01+January+2020) |
| **Q2** FRQ | [2. Algorithms on graphs](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms-on-graphs/) | 8 | 0.29 Easy | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=8edc06c0-8aba-4ac9-8301-c7f744c0b1f1&source_detail=WDM11%2F01+January+2020) |
| **Q3** FRQ | [4. Critical path analysis](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/critical-path-analysis/) | 9 | 0.45 Medium | 0.28 Low | 0.26 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=ebbbbd7c-1096-4cbe-8220-636dd8747b19&source_detail=WDM11%2F01+January+2020) |
| **Q4** FRQ | [1. Algorithms](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms/) | 13 | 0.46 Medium | 0.20 Low | 0.20 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=28fb977b-4b83-4f8a-aaf7-6d6c6242a1e4&source_detail=WDM11%2F01+January+2020) |
| **Q5** FRQ | [4. Critical path analysis](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/critical-path-analysis/) | 7 | 0.64 Hard | 0.20 Low | 0.38 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=9f508cff-c135-4e48-b79f-a72b902cce8e&source_detail=WDM11%2F01+January+2020) |
| **Q6** FRQ | [2. Algorithms on graphs](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms-on-graphs/) | 15 | 0.53 Medium | 0.20 Low | 0.23 Low | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=4a33d26a-1076-48f4-a1ee-6c46be292c52&source_detail=WDM11%2F01+January+2020) |
| **Q7** FRQ | [5. Linear programming](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/linear-programming/) | 18 | 0.41 Medium | 0.41 Medium | 0.38 Medium | [Go to Practice Hub](https://www.examsci.com/practice?set_id=e10d26ce-a57a-4414-85a8-df4e5d25bcd9&question_id=4d380b53-828f-45f3-a7bd-d7ebb92f5c77&source_detail=WDM11%2F01+January+2020) |

## Topics in this paper

- [3. Algorithms on graphs II](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms-on-graphs-ii/)
- [2. Algorithms on graphs](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms-on-graphs/)
- [4. Critical path analysis](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/critical-path-analysis/)
- [1. Algorithms](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/algorithms/)
- [5. Linear programming](https://www.examsci.com/topics/edexcel-ial/mathematics/decision-mathematics-1-wdm11/linear-programming/)

## Related papers

- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2020-october-wdm11-01/) — October 2020 — 8 questions · 75 marks — Free
- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2021-october-wdm11-01/) — October 2021 — 7 questions · 75 marks — Pro
- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2021-june-wdm11-01/) — June 2021 — 7 questions · 75 marks — Pro
- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2021-january-wdm11-01/) — January 2021 — 7 questions · 75 marks — Pro
- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2019-june-wdm11-01/) — June 2019 — 6 questions · 75 marks — Free
- [WDM11/01](https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2022-june-wdm11-01/) — June 2022 — 7 questions · 75 marks — Pro

## Paper FAQ

**How are the difficulty and complexity measures calculated?**

Each part is weighted by its official marks. Difficulty uses Easy 0.20, Medium 0.45 and Hard 0.75; algebraic complexity and text density and modelling use Low 0.20, Medium 0.45 and High 0.75. A Hard part worth 4 or more marks is down-weighted to marks^0.75, so the accessible starter steps inside a long structured question do not inflate the difficulty result. This paper's Difficulty Measure is 0.45 from 27 parts.

**What does the Difficulty Deviation show?**

It is the mark-weighted standard deviation of the part difficulty values around the paper mean. A value of 0 would mean every tagged part has the same difficulty; this paper's deviation is 0.16, so its parts are more mixed than a single-level paper.

**Is the Difficulty Ratio based on question counts or marks?**

It is based on official marks, not question counts. This paper's shares are 17.3% Easy, 62.7% Medium and 20.0% Hard; the three shares sum to 100% before rounding.

**Are these official difficulty ratings?**

No. They are derived from the platform's part-level difficulty and static-question-profile tags. They are not exam-board grade boundaries and are not calculated from candidate outcomes. Use them to compare the demand profile of papers, not to predict a grade.

**Why does each question row show its own measures?**

Each row recalculates the same mark-weighted formula from that question's parts. A single-part MCQ therefore shows the tag value directly, while a multi-part structured question blends the tags of its parts using the same Hard-part decay as the paper profile.

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Full page with native tables, bar charts and Practice Hub links: https://www.examsci.com/past-papers/edexcel-ial/mathematics/decision-mathematics-1-wdm11/2020-january-wdm11-01/