Logical Reasoning Tricks — Solve Puzzles 3x Faster

Logical Reasoning is the most time-consuming section in every competitive exam. These techniques help you structure your approach, reduce errors, and solve puzzles 2–3x faster.

Seating Arrangement — The Grid Method

The biggest mistake: solving linearly. Instead, build a grid or circle before reading all conditions.

Linear arrangements:

Draw the seats as boxes (1 to n)
Mark "definite" positions first (given directly)
Add "relative" clues (A is 2 seats right of B)
Use elimination for the rest

Circular arrangements:

Fix one person as reference (doesn't matter who — eliminates rotational ambiguity)
Place others relative to reference
Always note "facing centre" vs "facing outward"

Floors/Buildings:

List floors top-to-bottom in a column
Fill definites, then apply "above/below" clues
Look for contradictions — they narrow options fast

Puzzles — Box/Month/Year Types

Step 1: Identify the variables (people, items, attributes) Step 2: Draw a table with one variable as rows, others as columns Step 3: Use Y/N (Yes/No) or ✓/✗ to fill possibilities Step 4: When a cell is confirmed ✓, mark entire row and column as ✗ for that attribute

This elimination grid is 2x faster than trying to hold information in your head.

Blood Relations — Family Tree

Never solve blood relations without drawing a family tree.

Standard symbols:

Square = Male, Circle = Female
Horizontal line = Married couple
Vertical/slanted lines = Children

Common traps:

"X is the son of Y's father" — Y's father, not Y
"Only child" — no siblings, changes the tree completely
Gender-neutral names (like 'Kim', 'Alex') — wait for a pronoun to assign gender

Coded blood relations: Convert the code to plain language first, then draw the tree.

Syllogism — Venn Diagram Rule

Draw 3 overlapping circles for 3 statements. Fill each region:

"All A are B" → A circle is fully inside B circle
"Some A are B" → Circles overlap partially
"No A are B" → Circles don't overlap

Possibility questions: The answer can be true under at least one valid Venn diagram. Draw 2–3 diagrams for the extreme cases.

Negation trick: "Some are not" is the complement of "All are." If conclusion says "All A are C" and it's not true, then "Some A are not C" must be true.

Coding-Decoding — Pattern Recognition

Letter shifting: Find the shift (+3, −5, etc.) for the first pair, verify with the second pair, apply to the third.

Number coding: Calculate the relationship (sum of letters, position reversal, etc.) — look for arithmetic pattern.

Symbol coding: Match positions systematically. Don't guess — if 3 conditions are given, you should be able to decode any word.

Word coding: Each word maps to another word. Find which category the code belongs to (object→action, noun→adjective, etc.)

Direction Sense — Compass Grid

Always draw North-South-East-West before starting. Mark starting point as origin.

Standard: North is up, South is down, East is right, West is left.

Left turn: Rotate 90° anticlockwise from current direction Right turn: Rotate 90° clockwise from current direction

Calculate final position using net displacement: (total East − total West, total North − total South)

Distance from origin = √(x² + y²) where x is horizontal displacement, y is vertical.

Series — The Difference Method

Number series:

Calculate differences between consecutive terms
If differences are constant → arithmetic series
If differences form their own series → second-order difference
If ratio is constant → geometric series
If neither → look for alternating series (odd/even terms separate)

Letter series: Convert letters to numbers (A=1, Z=26) and apply number series techniques.

Input-Output — Operation Identification

Compare Step 0 (input) to Step 1: what changed? (sorting, shifting, adding?)
Verify the same operation from Step 1 to Step 2
Once operation is identified, apply directly to find any step

Common operations: arranging numbers in ascending/descending order (one element per step), shifting words, adding values.

Time Management in LR

Screen all sets first (2 minutes): Read first 2 lines of each set. Mark as Easy/Hard.
Attempt Easy sets first: Get guaranteed marks, build momentum
In a set, answer the sure questions: Don't get stuck on one hard question within a set
Time budget per set: 4–5 minutes for a 4-question puzzle set (1 minute/question)