Patwari Exam · Reasoning
Coding-Decoding in Reasoning
This note explains letter shift, reverse code, and place-value code methods for solving coding-decoding questions.
- Reasoning & Numerical Ability
- 5 min read
Verified 6 October 2026
Key Formulas & Methods
- Letter-shift code
- Letter shift: A→D, B→E (each +3) → CAT = FDW.
- Reverse code
- Reverse code: A=Z, B=Y (opposite of A) → RICE = IRXV.
- Place-value code
- Place-value code: A=1, B=2 … Z=26 → MATHS = 13+1+20+8+19 = 61.
- Mixed number-letter code
- Mixed number-letter: 1=A, 2=B → 3-1-20 = C-A-T = CAT.
- Word code
- Word code: "Tea" is called "Milk", "Milk" is called "Water" → what will Tea be called? → Milk.
- Symbol code
- Symbol code: A#B = add A to B, or A*B = A×B → understand the rule first.
- Exam tip
- Exam tip: work out the shift/pattern from the given example before applying it.
Frequently Asked Questions
How does a letter-shift code work?+
In a letter-shift code, every letter is moved forward by a fixed number — for example, A→D, B→E (each +3) turns CAT into the code FDW.
What is a place-value code?+
In a place-value code, every letter is replaced by its alphabetical position, e.g. A=1, B=2 … Z=26; on this basis MATHS = 13+1+20+8+19 = 61.
What is the best exam tip for solving coding-decoding questions?+
First identify the shift or pattern in the given example, then apply the same rule to the word asked about.