# Puzzles — The Grid Method for Day, Floor and Person Puzzles

Source: https://skills101.in/learn/reasoning/reasoning-puzzles — Skills101 free tutorial (Logical Reasoning). Updated 2026-11-09.

A puzzle gives you several people and several attributes — days, floors, colours, subjects — and clues that link them. The **grid method** turns it into simple elimination.

## 1. The grid

![A grid of people (Asha, Bilal, Chetan, Divya) against days (Mon to Thu). Asha is Tue and Chetan is Mon; the other cells are crossed out or still open](https://skills101.in/learn-img/reasoning/puzzle-grid.svg)

- Rows = people. Columns = the attribute (days, floors…).
- ✓ = definitely true, ✗ = impossible.
- **Each row and each column has exactly one ✓** (when everyone gets a different value).
- When a row has one ✓, cross out the rest of that row **and** that column.

## 2. A full example

*Four friends — Asha, Bilal, Chetan and Divya — each have an interview on a different day, Monday to Thursday.*

1. *Chetan's interview is on Monday.*
2. *Asha's interview is the day after Chetan's.*
3. *Bilal's interview is not on Thursday.*

**Solve:**

- Clue 1: Chetan = Mon ✓ → cross out Mon for everyone else.
- Clue 2: Asha = Tue ✓ → cross out Tue for Bilal and Divya.
- Bilal and Divya are left with Wed and Thu (the "?" cells in the picture).
- Clue 3: Bilal ≠ Thu → **Bilal = Wed**, **Divya = Thu**.

**Answer:** Mon Chetan, Tue Asha, Wed Bilal, Thu Divya.

## 3. Floor puzzles

Floors are like a vertical row. "Above" and "below" are like "right" and "left".

### Example
*Five people live on floors 1 (bottom) to 5 (top) of a building, one per floor. Kiran lives on floor 3. Mohan lives just above Kiran. Leela lives on the top floor. Nisha lives below Omar. Who lives on floor 1?*

- Kiran 3, Mohan 4, Leela 5.
- Floors 1 and 2 are left for Nisha and Omar. Nisha is below Omar → **Nisha 1**, Omar 2.

## 4. Two attributes at once

When each person has **two** attributes (e.g. a day **and** a city), use a table with one row per person and one column per attribute. Fill it as you go:

| Person | Day | City |
|---|---|---|
| Asha | Tue | ? |
| … | … | … |

Clues like "the person going to Pune goes on Wednesday" link the columns; write them next to the table until you can place them.

## The order to read clues

1. **Definite** clues ("X is on Monday").
2. **Relative** clues that touch a placed person ("Y is the day after X").
3. **Negative** clues ("Z is not on Thursday") — use them to eliminate.
4. If stuck, **branch**: take one open cell, try both values, and see which one breaks.

## Common mistakes

- Not crossing out the column after placing a ✓.
- Reading "between" as "immediately between".
- Writing too little: draw the grid even if the puzzle looks small.

## Quick recap

- Grid of people × values; ✓ and ✗.
- One ✓ per row and column → cross out the rest.
- Definite → relative → negative clues → branch if stuck.


Practice quiz and free certificate: https://skills101.in/learn/reasoning/reasoning-puzzles