Reasoning

Number & Letter Series Guide & Practice

Master arithmetic, geometric, alternating, Fibonacci, and letter series pattern recognition with explanations, shortcuts and mock sets. Explore dynamic solver blueprints, master fundamental equations, examine step-by-step solved examples, and practice with real exam-grade mock test sets.

Foundation & Concepts

1. Letter Series Foundation

  • Alphabetical Positions: Standard (A=1...Z=26).
  • EJOTY Concept: E=5, J=10, O=15, T=20, Y=25. Helps locate any letter quickly.
  • RHS Counting: To find the position of a letter from the Right Hand Side (Z to A), use: 27 - (Position from Left).
    • Example: The 10th letter from the left (J) is the (27-10) = 17th letter from the right.
  • Central Letter: To find the middle letter between two positions from the same side, take the average of their positions.
    • Example: Middle of 12th (L) and 20th (T) is (12+20)/2 = 16th (P).

2. Number Series Foundation

  • Sequence: A set of numbers following a specific mathematical rule.
  • Common Logic:
    • Addition/Subtraction (Constant or increasing/decreasing difference).
    • Multiplication/Division.
    • Squares and Cubes (n², n³, n²+1, etc.).
    • Fibonacci (Sum of previous two terms).

Patterns/Rules

  1. Arithmetic Series: Difference between consecutive terms is constant.
  2. Geometric Series: Each term is multiplied/divided by a constant factor.
  3. Alternating Series: Two or more different patterns running in parallel (e.g., terms 1, 3, 5 follow one rule; terms 2, 4, 6 follow another).
  4. Mixed Operator: Using multiple operations, e.g., (Term * 2) + 3.
  5. Letter Clusters: Patterns applied to groups of letters (e.g., SCD, TEF, UGH...).
  6. Continuous Pattern Series: Small letters with blanks that form a repeating rhythmic pattern (e.g., abc_bc_ab_).

Solved Examples

1Solved Example
Easy

Q1. Complete the series: 3, 6, 11, 18, 27, ?

2Solved Example
Moderate

Q3. Complete the series: SCD, TEF, UGH, ____, WKL

3Solved Example
Hard

Q6. Which set of letters completes the pattern? ab_accab_acc_bba_cabba_c

  • Options: (a) bcabb, (b) acbcc, (c) bbacc, (d) bcbba

Practice Question Papers

Practice Filters

Reasoning

Jun 2026

Series - Set 5 Practice Test

24 Qs
36 min
Hard
Taken by 1 student

Reasoning

Jun 2026

Series Practice Test

25 Qs
25 min
Medium
Taken by 1 student

Reasoning

Jun 2026

Series - Set 5 Practice Test

25 Qs
37 min
Medium
No attempts yet

Reasoning

Jun 2026

Series - Set 4 Practice Test

25 Qs
37 min
Medium
No attempts yet

Reasoning

Jun 2026

Series - Set 3 Practice Test

25 Qs
37 min
Medium
No attempts yet

Reasoning

Jun 2026

Series - Set 2 Practice Test

25 Qs
37 min
Medium
No attempts yet

Reasoning

Jun 2026

Series - Set 1 Practice Test

25 Qs
37 min
Medium
No attempts yet

Reasoning

Jun 2026

Series - Set 4 Practice Test

25 Qs
37 min
Hard
No attempts yet

Reasoning

Jun 2026

Series - Set 3 Practice Test

25 Qs
37 min
Hard
No attempts yet

Reasoning

Jun 2026

Series - Set 2 Practice Test

25 Qs
37 min
Hard
No attempts yet

Reasoning

Jun 2026

Series - Set 1 Practice Test

25 Qs
37 min
Hard
No attempts yet

Reasoning

Jun 2026

Series - Set 5 Practice Test

25 Qs
37 min
Easy
No attempts yet

Reasoning

Jun 2026

Series - Set 4 Practice Test

25 Qs
37 min
Easy
No attempts yet

Reasoning

Jun 2026

Series - Set 3 Practice Test

25 Qs
37 min
Easy
No attempts yet

Reasoning

Jun 2026

Series - Set 2 Practice Test

25 Qs
37 min
Easy
No attempts yet

Reasoning

Jun 2026

Series - Set 1 Practice Test

25 Qs
37 min
Easy
No attempts yet

Reasoning

Jun 2026

Series Practice Test

25 Qs
25 min
Hard
No attempts yet

Reasoning

Jun 2026

Series Practice Test

25 Qs
25 min
Easy
No attempts yet