Module 2: S4 Reasoning
Topic 1: Seating Arrangement & Logic Puzzles
1 The Solvers' Algorithm (How to Begin)
Candidates fail puzzles not because they lack logic, but because they lack a reading strategy. Never draw your final diagram based on the first sentence.
[STEP 1]: Scan & Categorize
Read the entire puzzle once without drawing. Categorize the clues into:
★ Definite Clues (A sits 2nd to the left of B)
★ Relative Clues (A and C are neighbors)
★ Negative Clues (D does not teach Math).
Read the entire puzzle once without drawing. Categorize the clues into:
★ Definite Clues (A sits 2nd to the left of B)
★ Relative Clues (A and C are neighbors)
★ Negative Clues (D does not teach Math).
[STEP 2]: The Anchor Point
ALWAYS start drawing with a Definite Clue that connects to the highest number of variables. If A is mentioned in 3 different clues, place A first.
ALWAYS start drawing with a Definite Clue that connects to the highest number of variables. If A is mentioned in 3 different clues, place A first.
[STEP 3]: Projection (The Split)
If a clue gives two possibilities (e.g., C can be on the extreme left OR extreme right), draw two separate diagrams simultaneously. Do not try to hold multiple realities in your head.
If a clue gives two possibilities (e.g., C can be on the extreme left OR extreme right), draw two separate diagrams simultaneously. Do not try to hold multiple realities in your head.
2 Spatial Orientation (Linear & Circular)
Circular: Facing the Center
Master Rule: If facing CENTER, Left = Clockwise. Right = Anti-Clockwise. If facing OUTSIDE, the rule reverses entirely!
Linear: Two Parallel Rows
Master Rule: For the South-facing row, the solver's Left/Right is reversed. Never map your own left/right to a South-facing person.
3 Language Deciphering Traps
⚠️ "AND" vs. "WHO"
This is the most common reason candidates fail multi-variable puzzles. Pay absolute attention to the conjunction used to connect clauses.
- "A sits 2nd to the right of B, AND sits opposite to C."
➡ 'And' / 'But' refers to the FIRST person (A is opposite C). - "A sits 2nd to the right of B, WHO sits opposite to C."
➡ 'Who' / 'Whom' / 'Which' refers to the SECOND person (B is opposite C).
Between vs. Exactly Between
Phrase: "A is between B and C"
Trap: Assuming the order is B - A - C.
Reality: The order could be C - A - B. Also, they may not be adjacent! (e.g., B - X - A - Y - C).
Trap: Assuming the order is B - A - C.
Reality: The order could be C - A - B. Also, they may not be adjacent! (e.g., B - X - A - Y - C).
Phrase: "A is exactly in the middle of B and C"
Reality: The distance from B to A is equal to the distance from A to C.
Reality: The distance from B to A is equal to the distance from A to C.
Phrase: "A sits immediate left of B"
Reality: There are ZERO seats between them.
Reality: There are ZERO seats between them.
4 Contextual Puzzle (The Grid Method)
Scenario: Three school administrators (Principal, Vice-Principal, Headmaster) are assigned to three different tasks (Timetable, Budget, Discipline).
- 1. P is not the Principal.
- 2. The Vice-Principal handles Discipline.
- 3. Q handles the Budget.
- 4. R is either the Principal or the Headmaster.
Grid Solving Technique: When variables (Name + Role + Task) are mixed, use a Cross-Elimination Matrix. Every time you place a '✓', cross out ('✗') the rest of that row and column.
| Name | Principal | Vice-Prin | Headmaster | Timetable | Budget | Discipline |
|---|---|---|---|---|---|---|
| P | ✗ (Clue 1) | ✗ | ✓ (Deduced) | ✗ | ✗ | ✗ |
| Q | ✗ | ✓ (Deduced) | ✗ | ✗ | ✓ (Clue 3) | ✗ |
| R | ✓ (Deduced) | ✗ | ✗ (Clue 4) | ✗ | ✗ | ✗ |