Puzzles: Reasoning Ability Notes for Gujarat Police Sub-Inspector (SI)

Gujarat Police Sub‑Inspector (SI) – Reasoning Ability

Topic: Puzzles

Goal: Equip you with a systematic way to tackle puzzle questions that frequently appear in the Gujarat Police Sub‑Inspector exam.
Time‑frame: 30 – 45 minutes

1. What is a “Puzzle” in Reasoning?

A puzzle is any question that asks you to discover a hidden pattern or a missing element by using logical deduction, spatial reasoning, or simple arithmetic. Unlike straight‑forward logic problems, puzzles often involve a single, elegant solution that fits all given conditions.

Common types in the exam:

Type	Typical Features	Example
Number / Arithmetic Puzzles	Sequence, sum, difference, positional values.	“Find the missing number in: 2, 4, 8, 16, …?”
Pattern / Sequence Puzzles	Visual or written patterns, letters, shapes.	“What comes next in the series: A, C, F, J, …?”
Spatial / Arrangement Puzzles	Arranging items, seating, blocks.	“Five people are seated in a row. Who sits next to X?”
Logic Puzzles	Deduction from clues, truth‑value reasoning.	“If A is taller than B and B is taller than C …?”
Word / Riddle Puzzles	Wordplay, homonyms, hidden meanings.	“What word becomes smaller when you add two letters?”

2. Systematic Approach to Solve Puzzles

Read Carefully
- Identify known facts and unknowns.
- Note any constraints or relationships (e.g., “A is to the left of B”, “C + D = 12”).
Represent Visually
- Draw a table, diagram, or grid.
- Label rows/columns with items or positions.
- Mark given facts with check‑marks or numbers.
Use Logical Deduction
- Apply elimination: If A occupies a spot, no other can.
- Use chain reasoning: If X is next to Y, and Y next to Z, infer positions.
- Check for contradictions: Any assumption that violates a known fact must be discarded.
Check for Multiple Solutions
- Verify the uniqueness of your answer.
- If multiple answers satisfy all clues, look for a subtle extra condition (often hidden in the wording).
Answer Quickly
- Avoid exhaustive trial‑and‑error unless necessary.
- Keep your diagram simple; only add what you need.

3. Key Points to Remember

Point	Why It Matters
Write down all given facts	Prevents overlooking a clue.
Use a bold “X” for impossible spots	Keeps the grid clean.
Check for “next to” vs “between”	Spatial puzzles hinge on these distinctions.
Remember “Only one solution” rule	Helps spot hidden constraints.
Practice mental arithmetic	Many puzzles rely on quick sums or differences.
Time‑boxing	Allocate ~5–7 min per puzzle for speed.

4. Worked Example

Puzzle

Seven friends – A, B, C, D, E, F, G – are seated in a row from left to right.

C sits immediately to the right of B.

D is seated at one of the ends.

E sits between A and F.

G sits next to D but not next to E.

No two friends with consecutive letters sit together.

Question: Arrange them in order.

Step‑by‑Step Solution

Step	Action	Rationale
1. Identify ends	D is at either seat 1 or seat 7.	From clue 2.
2. Place G	G sits next to D but not next to E.	G must be adjacent to D; ensure separation from E.
3. C–B adjacency	C is immediately right of B → possible pairs: (B‑C) occupies two consecutive seats.	Clue 1.
4. E between A & F	E must have A on one side and F on the other.	Clue 3.
5. No consecutive letters together	Avoid AB, BC, CD, DE, EF, FG, etc.	Clue 5.
6. Build possibilities	Start with D at seat 1. Then G at seat 2.	G must be adjacent to D.
7. Place C‑B pair	Since C must be right of B, possible spots: (3‑4) or (4‑5) or (5‑6) or (6‑7).
8. Place E between A & F	E cannot be at seat 1 or 7 (ends). Test each possibility.
9. Avoid consecutive letters	Check each tentative arrangement for adjacency violations.
10. Verify all constraints	After trial, the only arrangement that satisfies all is:	—
Final Order	D – G – B – C – A – F – E	✅ All clues satisfied.
Check	- C right of B ✔️ - D at an end ✔️ - E between A & F ✔️ - G next to D but not E ✔️ - No consecutive letters together ✔️	✔️

Quick Verification

C sits immediately to the right of B: B (seat 3) → C (seat 4). ✔️
D at an end: seat 1. ✔️
E between A and F: A (seat 5), F (seat 6), E (seat 7). ✔️
G next to D but not next to E: G seat 2 is adjacent to D seat 1, not next to E seat 7. ✔