Unit 14
Ordering Deduction
About this unit
Place people, objects, or events in the correct order — or determine what must, could, or cannot be in a specific position — using a set of positional clues. Questions range from simple 4-person linear arrangements to complex 8-person circular seating, relay handovers, and multi-criteria ranking puzzles.
What types of questions will you face?
- 1Linear ordering: 4-6 people in a row with "left of", "right of", and "not at end" constraints
- 2Circular seating: 6-8 people around a table with "opposite", "adjacent", and relative-direction constraints
- 3Relay/handover chain: trace an object passing through a sequence of handovers at specific times
- 4Multi-criteria ranking: rank people by two criteria simultaneously (time AND score) using clues
- 5Partial ordering: given 3 facts about relative positions, determine what else MUST or CANNOT be true
- 6"Valid arrangement" questions: given 4 possible orderings, identify the one that satisfies all rules
Skills you will build
- Tracking multiple positional constraints (before/after, adjacent, not adjacent) simultaneously
- Building up valid arrangements step-by-step from the most constrained element first
- Applying "opposite in a circle" and "adjacent" rules for circular arrangements
- Tracing relay handover chains forward in time
- Determining what must be true vs. what could be true when the arrangement isn't fully fixed
- Using elimination to discard invalid arrangements quickly
By the end of this unit, you will be able to
- Solve any 4-8 person linear or circular arrangement puzzle
- Trace relay chains across time to find who holds an item at any point
- Determine fixed positions and free positions in a partially constrained arrangement
- Answer "must be true / cannot be true" ordering questions reliably under time pressure
Difficulty profile
The hardest unit by average score (3.82). Simple 3-4 element orderings with one chain are Easy; circular arrangements with 6-8 people and multiple constraint types, relay chains, and multi-criteria rankings are Very Difficult. Mastery here significantly boosts your overall TS score.
Exam tip: Ordering Deduction
Start with the person/item with the most constraints — they are easiest to place. Then use each placed element to constrain the remaining ones. For circular arrangements, fix one person's seat first (the one with a "directly opposite" clue) then fill in from there.
Give Your Child the Best Chance at Selective Entry
Join NSW families preparing their children for the Selective Schools Placement Test with the most realistic online Selective practice tests available. First tests free—no credit card required.
Claim Your Free Selective Practice Tests