RRB NTPC Floor-Based Puzzle

Each person/object occupies exactly one floor 2. No two people can live on the same floor 3. Ground floor is numbered 1, then 2, 3, etc. 4. Top floor means highest numbered floor 5. 'Above' means higher numbered floor, 'Below' means lower numbered floor Key Formula Patterns: For n-floor building: Total arrangements possible = n

(n+1)/2 for odd floors, n/2 or (n/2)+1 for even floors Floors between X and Y = |X-Y| - 1

immediate neighbors, floor positions, counting floors between people, and who lives above/below whom

Create a simple grid with floors (1-7) as columns and people (A-G) as rows. Mark 'X' for impossible positions and 'O' for confirmed positions. This visual method reduces solving time by 40%

7 people (A,B,C,D,E,F,G) live on floors 1-7

When given 'A is 2 floors above B', immediately list all valid (B,A) pairs before reading other conditions 2

Quickly identify even (2,4,6) and odd (1,3,5,7) floors to eliminate impossible combinations 3

For 'immediately above/below', mark them as (n, n+1) pairs Common Trap - The #1 Mistake: Students confuse 'above' with 'immediately above'. 'A lives above B' means A's floor number > B's floor number (any gap allowed). 'A lives immediately above B' means A's floor = B's floor + 1. This confusion costs 2-3 marks per exam. Always read 'immediately' carefully!