Coding-Decoding Formula
Coding-Decoding formulas and a topic-wise mock test for logical reasoning placement exams like TCS NQT, Infosys, and Wipro. Revise, then practice.
Key Coding-Decoding Formulas
Common Coding-Decoding Patterns
Here are the most used tricks you'll see in exams:
- A. Letter Shifting: New Letter = Original Letter Position ± n
- B. Reverse Order: Letters are reversed before applying any shift
- C. Opposite Letters: Opposite = 27 - Letter Position
- D. Alternating Shifts: Different shifts for alternate letters
- E. Number Coding: Use alphabet positions (A=1, B=2… Z=26)
- F. Word + Number Mix: Add sum/difference of positions
Quick Step-by-Step Solving Approach
Compare the given word & its code → Look for position changes.
- Check for a constant difference between letters (forward/backward)
- See if the word is reversed before/after shifting
- Check if opposite letters or number coding is used
- Once the pattern is clear → apply it to the new word
Placement-Style Examples
Practice with these common patterns:
- Example 1: 'BOOK' → 'ERRO' (+3 shift), so 'PEN' → 'SHQ'
- Example 2: 'MOBILE' → 'NPDJMF' (+1 each), so 'LAPTOP' → 'MBQUQP'
- Example 3: 'DOG' → 26 (sum of positions), so 'CAT' → 24
- Example 4: 'BAT' → 'YZG' (opposite letters), so 'CAT' → 'XZG'
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