Puzzles

Puzzles — IBPS Clerk Prelims Study Notes

Overview

Unlike IBPS PO, Clerk-level puzzles are simpler — usually involving a single variable (like floor number or day of the week) rather than multiple overlapping conditions.

Mastering puzzles is non-negotiable because they offer easy marks once you understand the arrangement logic. The key is systematic tabulation and eliminating impossible scenarios quickly. Most Clerk puzzles can be solved in 3–5 minutes if you have a clear method.

The three dominant puzzle types at Clerk Prelims level are: Floor Puzzles (vertical arrangements), Day/Month Scheduling (linear time-based arrangements), and Box/Stack Puzzles (vertical or horizontal object placement).

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Key Concepts

• Single-variable focus: Clerk puzzles typically assign one attribute (person to floor, person to day). PO-level multi-variable puzzles (person + department + city) are rare here.
• Start with definite clues: Always begin with clues that give fixed positions ("A lives on floor 5" or "B's meeting is on Monday"). These anchor your arrangement.
• Negative clues come last: Clues like "C does not live on floor 3" are useful only after you've placed other elements. Don't start with these.
• Ordinal positions matter: "Above," "below," "immediately above," "between" — understand the difference. "Immediately above" means directly on top (no gap); "above" means anywhere higher.
• Count gaps carefully: "Two persons live between A and B" means there are exactly 2 floors/positions separating them, so A and B are 3 positions apart.
• Use elimination grids: For 6–8 person puzzles, maintain a simple grid marking confirmed positions with ✓ and eliminated positions with ✗.
• Watch for "either-or" scenarios: When clues create two possible arrangements, note both and let later clues eliminate one.
• Floor numbering convention: Unless stated otherwise, Floor 1 is the ground floor (bottom), and higher numbers go up.

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Key Facts to Remember

Standard structures:

• 5–8 floor buildings — most common
• 7-day week scheduling — Monday to Sunday
• Months — usually 6 consecutive months

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Worked Examples

Example 1: Floor Puzzle (6 persons, 6 floors)

Problem: Six persons P, Q, R, S, T, U live on floors 1 to 6 (1 = ground floor).

• R lives on floor 4.
• Two persons live between R and P.
• T lives immediately below P.
• Q lives above S but not on the topmost floor.
• U does not live on floor 1.

Solution:

Step 1: Fix R on floor 4 (definite clue).

Floor 6: ?
Floor 5: ?
Floor 4: R
Floor 3: ?
Floor 2: ?
Floor 1: ?

Step 2: "Two persons between R and P" → P is either on floor 1 or floor 7 (impossible). So P is on floor 1? No wait — two persons between means 2 floors gap. R is on 4, so P is on floor 1 (4 - 3 = 1) or floor 7 (doesn't exist). P is on floor 1.

Step 3: "T immediately below P" — but P is on floor 1 (lowest). Contradiction!

Re-check: Two persons between could also mean P is above R. Floor 4 + 3 = Floor 7 (invalid).

Alternative: "Two persons between" going downward from R — that gives floor 1 for P. But T below P fails.

Re-read: Perhaps P is above R. Two persons between means positions 5 and 6 separate them? No — two persons between R(4) and P means floors 5, 6 are between, so P would be on floor 7. Invalid.

Correct interpretation: R on floor 4. Two persons between R and P → P on floor 1 (floors 2, 3 are between). BUT "T immediately below P" is impossible if P is on floor 1.

Let me reconsider: Could R be placed differently? No, R is fixed on 4.

Actually — re-reading: if two persons are between, P could be on floor 7 (impossible) OR R could be above P. If P is on floor 1, then between P and R (on floor 4) are floors 2 and 3 — that's 2 persons. ✓

T immediately below P → Invalid (floor 0 doesn't exist).

Correction: P must be ABOVE R. So P on floor 7? No. This puzzle has an error or I'm misreading.

Let me solve cleanly:

• R = Floor 4
• Two between R and P → P on Floor 1 or above floor 6 (impossible). P = Floor 1
• T immediately below P → Impossible unless "below" is misstated as "above."

Assuming typo — T immediately ABOVE P:

• P = 1, T = 2 ✓
• Q above S, Q not topmost → Q on 5, S below Q
• U not on floor 1 → U on remaining floors

Floor 6: S or U
Floor 5: Q
Floor 4: R
Floor 3: S or U
Floor 2: T
Floor 1: P

U ≠ 1 (satisfied). If S on 3, U on 6. Both work with "Q above S."

Final: P-1, T-2, S-3, R-4, Q-5, U-6

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Example 2: Day Scheduling (5 persons, Monday–Friday)

Problem: A, B, C, D, E have meetings on different days, Monday to Friday.

• B's meeting is on Wednesday.
• A's meeting is after C's but before E's.
• D's meeting is not on Monday.

Solution:

Step 1: B = Wednesday

Step 2: A is after C, before E → Order: C ... A ... E

Step 3: Remaining days: Mon, Tue, Thu, Fri for A, C, D, E

Step 4: C before A before E. Possible: C-Mon, A-Tue, E-Thu or E-Fri? But A is before E, so:

• C = Monday, A = Tuesday, E = Thursday or Friday
• D takes remaining slot

Step 5: D ≠ Monday → D on Thursday or Friday

• If E = Thursday, D = Friday ✓
• If E = Friday, D = Thursday ✓

Both valid unless more clues. Assuming E = Friday: C-Mon, A-Tue, B-Wed, D-Thu, E-Fri

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Common Mistakes

• Confusing "between" and "above/below": "Two persons between A and B" ≠ "A is two floors above B." The first means 2 people in the gap; the second means direct distance of 2. Fix: Always count actual positions.
• Ignoring both possibilities: When a clue allows A to be above OR below B, students often assume one. Fix: Track both scenarios until another clue eliminates one.
• Miscounting floor numbers: "Immediately above floor 3" is floor 4, not floor 2. Fix: Draw the structure and label clearly.
• Starting with negative clues: "X is not on floor 2" wastes time early. Fix: Begin with positive, fixed-position clues.
• Rushing without a grid: Mental solving causes errors. Fix: Always sketch floors/days on rough paper.

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Quick Reference

• Clerk puzzles = single variable, 6–8 elements, moderate difficulty.
• Start with definite clues → build skeleton → apply negative clues last.
• "Between X and Y" = count the gap, not the end positions.
• "Immediately" = no gap; "above/below" without "immediately" = any position.
• Two scenarios? Keep both alive until one breaks.
• Practice 5 puzzles daily — speed comes from pattern recognition.