RPF Constable – Reasoning Ability
Topic: Puzzles
Puzzles are a popular type of reasoning question that test your ability to spot patterns, sequential logic, and relationships between objects or numbers. They are usually short, time‑constrained, and require a sharp eye for detail.
1. Simple Explanation
A puzzle in reasoning tests is a problem that asks you to deduce the next element, the missing element, or the correct arrangement based on a set of given clues. The key is pattern recognition – whether it’s a numerical progression, a sequence of shapes, letters, or logical relationships between items.
2. Key Points & Strategies
| # | What to Look For | How to Approach | Example Hint |
|---|---|---|---|
| 1 | Arithmetic / Geometric Progression | Compute differences or ratios between consecutive terms. | 2, 4, 8, 16 → next = 32 |
| 2 | Alternating Patterns | Split into even/odd positions; each sub‑sequence has its own rule. | 3, 6, 9, 12, 15 → odd terms 3,9,15 (add 6) |
| 3 | Positional/Spatial Patterns | Visualise arrangement (rows, columns, circles). | 5‑point star, missing point |
| 4 | Letter/Word Patterns | Shift letters, count vowels/consonants, or use word lengths. | AB, BC, CD → next = DE |
| 5 | Logical Relationships | Use “if‑then” statements, exclusions, or “only one” rules. | “Only one person can be both a dancer and a singer” |
| 6 | Parity/Modular Arithmetic | Check even/odd, mod 3, mod 5 patterns. | Numbers ending in 1,4,7,0 → next ends in 3 |
| 7 | Symmetry & Reflection | Mirror images, rotational symmetry. | Mirror of L gives J |
| 8 | Elimination | Rule out impossible options first. | If A is not 3rd, B cannot be 4th, etc. |
| 9 | Use of “Given” vs “To Find” | Separate known facts from unknowns. | “Given X, find Y” |
| 10 | Time Management | Allocate 1–2 minutes; skip if stuck, return later. |
3. Worked Example
Problem
Find the missing number in the series:
2, 5, 10, 17, 26, ?, 50
Step‑by‑step Solution
-
Look at differences between consecutive terms
- 5 – 2 = 3
- 10 – 5 = 5
- 17 – 10 = 7
- 26 – 17 = 9
The differences are: 3, 5, 7, 9 → They increase by 2 each time.
-
Predict the next difference
- Next difference = 9 + 2 = 11
-
Compute the missing term
- Missing term = 26 + 11 = 37
-
Verify with the next given term
- Next difference after 37 should be 13 (since pattern continues +2).
- 37 + 13 = 50 → ✔️
Answer
The missing number is 37.
4. Quick Revision Summary
- Identify the type of pattern: arithmetic, geometric, alternating, positional, letter, logical, parity, symmetry, etc.
- Compute differences or ratios for numeric sequences.
- Separate sub‑sequences if alternation is present.
- Visualise arrangements for spatial puzzles.
- Use elimination to discard impossible options.
- Check consistency with the entire series after guessing.
- Manage time: 1–2 min per puzzle; skip and return if stuck.
Final Tip
Practice a variety of puzzles (number, letter, spatial, logical) daily. The more patterns you see, the quicker you’ll spot them under exam conditions. Happy puzzling!