Logical Reasoning – Concepts and Questions

1. Number Series

• Identify the pattern: arithmetic (±), geometric (× or ÷), squares, cubes, or alternating patterns.
• Common types include:
  • +/- series (e.g., +2, +4, +6…)
  • ×/÷ series (e.g., ×2, ÷3…)
  • Square/cube-based or Fibonacci-type sequences

2. Alphabet Series

• Each letter corresponds to a numeric position (A=1 to Z=26)
• Look for patterns in gaps between letters, reverse sequences, or alternate sequences

3. Coding-Decoding

• Letter Shifts: A = 1, B = 2 … Z = 26. Apply +/− shifts to code/decode
• Substitution: Words replaced with other fixed words or letters based on a rule
• Jumbling: Letters of a word rearranged following a pattern

4. Blood Relations

• Use a family tree diagram:
  • M = Male, F = Female
  • Single lines = Siblings, double line = Marriage
• Typical questions involve: son/daughter-in-law, cousin, uncle/aunt, etc.

5. Direction Sense

• Standard compass directions: North, South, East, West
• Turning Left = 90° anti-clockwise; Turning Right = 90° clockwise
• Use diagrams for tracking movement

6. Seating Arrangement

• Types: Linear, Circular, Square, Rectangular arrangements
• Key clues: Left/Right of person, Facing inside/outside, Immediate neighbor, etc.
• Draw and eliminate possibilities to fix positions logically

7. Syllogisms

• Use Venn Diagrams for better clarity
• Basic Statements:
  • All A are B
  • Some A are B
  • No A is B
• Conclusions must follow necessarily based on given statements

8. Analogy

• Relationship between first pair = relationship to be applied to second pair
• Types: Word meaning, logic, numbers, figures, etc.

9. Classification (Odd One Out)

• Identify the odd term based on logic: numerical pattern, meaning, group type, etc.
• Common themes: fruits vs animals, primes vs evens, etc.

10. Statement & Conclusion

• Read statements carefully, avoid assumptions
• Conclusions must follow strictly from the given statements

11. Statement & Assumption

• Assumption is something that must be true for the statement to make sense
• Look for hidden beliefs or implicit logic

12. Statement & Argument

• Strong argument: Direct, relevant, impactful
• Weak argument: Emotional, irrelevant, vague
• Judge based on logic, not personal bias

13. Cause and Effect

• Identify if one event leads to another
• Use real-world logic — effect should follow cause, not vice versa

14. Calendar

• Odd Days Concept: Days beyond complete weeks (7 days)
• 1 normal year = 1 odd day; 1 leap year = 2 odd days
• Use known dates as anchors (like Jan 1, 1900 = Monday)

15. Clock

• Angle between hands = $|30H – \frac{11}{2}M|$
• Hands meet: Every 65 minutes
• Opposite each other: Every 60 minutes