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Topic summary · Decision maths (D1)

Matchings summary

Bipartite matching pairs two sets such as people and tasks. Alternating paths improve incomplete matchings.

Files: D1-Matchings.pdf · D1-Matchings answers.pdf · free public downloads · diagrams in the PDFs

Key learning points

  • Draw the bipartite graph with the two parts clearly separated.
  • Distinguish maximal from maximum matchings.
  • Augmenting paths flip edges to increase matching size by one.
  • State the final matching explicitly.

Worked example 1 — Augmenting path

What does an augmenting path achieve?

Working

increases the matching by one\text{increases the matching by one}

Flip matched and unmatched edges along the path.

Worked example 2 — Draw the bipartite graph with the two parts clearly

Use this method from the Matchings sheet: Draw the bipartite graph with the two parts clearly separated.

Working

Attempt a matching question on the sheet, then check the Answers PDF.\text{Attempt a matching question on the sheet, then check the Answers PDF.}

Each key learning point matches a question type on the printable worksheet.

Worked example 3 — Distinguish maximal from maximum matchings

Use this method from the Matchings sheet: Distinguish maximal from maximum matchings.

Working

Attempt a matching question on the sheet, then check the Answers PDF.\text{Attempt a matching question on the sheet, then check the Answers PDF.}

Each key learning point matches a question type on the printable worksheet.

Worked example 4 — Augmenting paths flip edges to increase matching size

Use this method from the Matchings sheet: Augmenting paths flip edges to increase matching size by one.

Working

Attempt a matching question on the sheet, then check the Answers PDF.\text{Attempt a matching question on the sheet, then check the Answers PDF.}

Each key learning point matches a question type on the printable worksheet.

Worked example 5 — State the final matching explicitly

Use this method from the Matchings sheet: State the final matching explicitly.

Working

Attempt a matching question on the sheet, then check the Answers PDF.\text{Attempt a matching question on the sheet, then check the Answers PDF.}

Each key learning point matches a question type on the printable worksheet.

Scaffolded Learning Sheet and answers (PDFs)

This page is a short, searchable overview for revision and search engines. Use the Scaffolded Learning Sheet first, then the Answers PDF for a full written solution. The printable PDFs remain the main classroom resource.