Question 1
SEAMO self-study edition 2027; not an official 2027 paper. Original source years are retained. 25 questions, 90 minutes; Q1–10: 3 points, Q11–20: 4 points, Q21–25: 6 points, total 100. Original response types and all subparts are preserved. Verified is an editorial convention; source defects, necessary assumptions and unresolved mathematical uncertainty are disclosed.
The annulus shown is divided into 14 regions. Each region is painted one colour. What is the minimum number of colours needed so that no two adjacent regions share a colour? Regions are adjacent when they share a boundary segment.
The annulus shown is divided into 14 regions. Each region is painted one colour. What is the minimum number of colours needed so that no two adjacent regions share a colour? Regions are adjacent when they share a boundary segment.