Alphanumeric Series is one of the simplest yet most scoring topics in the reasoning section of SSC, Banking, RRB, and other competitive exams. It combines letters, numbers, and symbols in a sequence, and questions are framed by applying patterns, positions, and codes. In this blog, we will cover its definition, types, shortcuts, formulas, solved questions, and more.
What Is Alphanumeric Series in Reasoning?
Alphanumeric Series is a sequence-based reasoning topic where a string contains a mix of alphabets, numbers, and symbols arranged in a specific order. You are asked to identify patterns, apply logic, and answer position-based or coded questions.
These questions assess:
- Pattern recognition skills
- Logical decoding ability
- Visualization of positions and gaps between characters
They appear frequently in exams because they are:
- Quick to attempt
- Easy to master with practice
- Ideal for scoring full marks in seconds
Why Is Alphanumeric Series Important in Competitive Exams?
Alphanumeric series is an important topic in competitive reasoning sections because it tests candidates’ ability to handle pattern-based data within strict time limits.
| Exam | No. of Questions | Difficulty |
| SSC CGL / CHSL | 1–2 | Easy |
| IBPS PO / SBI PO | 1–2 | Moderate |
| RRB NTPC / Group D | 1 | Easy |
| State PSC / Police | 1–2 | Moderate |
Alphanumeric Series Reasoning Short Notes
Some of the terms used in Alphanumeric Series are as follows:
| Term | Meaning |
| Position Value | A=1, B=2, …, Z=26 |
| Reverse Alphabet Value | Z=1, Y=2, …, A=26 |
| Skip Letters | Letters with +1 or -2 gaps |
| Symbols in Series | Placed to break pattern or test symbol count |
| Number-Alpha Matching | Number relates to position or count of alphabet |
Alphanumeric Series Reasoning Concepts
Concepts that are mostly used in Alphanumeric Series are as follows:
| Concept | Details |
| Forward Alphabet Order | A to Z = 1 to 26 |
| Reverse Alphabet Order | Z to A = 1 to 26 |
| Fixed Gap Letters | E.g., Every 2nd letter = A, C, E… |
| Symbol Coding | Position-based logic (e.g., 3rd symbol from left) |
| Number to Letter Mapping | E.g., 1 = A, 2 = B, … |
| Letter to Number Mapping | E.g., C = 3, J = 10 |
What Are the Types of Alphanumeric Series Questions in Reasoning?
Alphanumeric series questions appear in several forms. Below are the major types:
- Direct Letter/Number Positioning: Find the character at a specific position from left or right in the series.
- Symbol-Based Questions: Count or identify specific symbols between two characters (letters or numbers).
- Coded Series: Apply logic based on position shifts, reverse order, or fixed intervals to decode patterns.
- Puzzle-Pattern Based: Solve multi-step logic involving combinations of letters, numbers, and symbols in a sequence.
Alphanumeric Series Formulas for Reasoning
Though there are no fixed formulas to solve this type of question, some formulas that mostly work while solving alphanumeric questions are as follows:
- A to Z = 1 to 26, and Z to A = 1 to 26 (reverse)
- Count vowels/consonants in a sequence
- Use +n/-n logic for alphabets: A + 2 = C
- Use odd-even logic in numeric values
- Convert letters to numbers: A = 1, B = 2…
- Count characters at even/odd positions for logic-based coding
Alphanumeric Series Tricks for SSC CGL and Other Exams
Some of the tricks to solve alphanumeric series questions are as follows:
- Convert all letters to position values (A=1, B=2, …, Z=26)
- Reverse count if asked from right or end
- Focus on even and odd positions when symbols are involved
- Circle symbols and quickly count between elements
- Use elimination when options seem close
- Underline or box the required positions in the series
- Practice mentally identifying vowel/consonant positions
- Track repeated blocks of letters/symbols
- For large series, divide into sets of 5 or 10
- Always read question carefully
Solved Alphanumeric Series Questions from 2024–25 Exams
Memory-based questions from recent exams:
Q1. (Asked in SSC CHSL 2024 Tier 1 – Shift 2)
Series: 9 B % 3 F 7 * D 2 & H 6 # K
Q. How many symbols are there between ‘F’ and ‘H’?
Answer: 3
Explanation: Between F and H: 7 * D 2 & → 3 symbols.
Q2. (From IBPS PO Prelims 2024 Mock)
Series: M 8 & P $ 1 T % 6 J
Q. What is the 5th element to the left of ‘%’?
Answer: &
Explanation: % is at position 8; 5th to the left = 3rd → &
Q3. (Based on Memory – RRB NTPC 2024 Stage 1)
Series: 4 A $ 6 B * 7 C % D
Q. How many alphabets are there between * and %?
Answer: 1
Explanation: Between * and %: 7 C → only one alphabet.
Alphanumeric Series Concepts for Bank Exams
Bank exams like IBPS PO, SBI Clerk, and RBI Assistant often test:
- Coded series with logic like vowel + odd number + symbol
- Questions involving left/right shifting
- Reverse decoding of sequences
Example (SBI PO Mains Pattern):
Series: T @ 9 G $ 6 E * 3
Q. If all symbols are removed, what is the 4th from the right?
After removal: T 9 G 6 E 3 → 4th from right = G
Common Mistakes to Avoid while Solving Alphanumeric Series
While solving Alphanumeric Series questions candidates must avoid the below mentioned mistakes:
- Ignoring Directions (Left/Right): Always visualize the full series before counting.
- Miscounting Positions: Start from 1, not 0; double-check with fingers if unsure.
- Confusing Letters with Numbers: Highlight or separate letters, numbers, and symbols in rough.
- Overcomplicating Simple Logic: Re-read the question if stuck — it’s often simpler than it appears.
- Skipping Series Type Identification: First identify whether the question is direct, symbol-based, or coded.
FAQs
Highlight symbols in the series and count only those falling exactly between or around the target characters.
Yes, especially in prelims. These appear in both direct and coded forms.
Underline or circle each category while reading the series; maintain clear separation in rough work.
Count from the end of the series manually or subtract position from total length + 1.
Z = 1, Y = 2, …, A = 26 – used in reverse alphabet logic-based questions.
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