Coding-Decoding
Coding-decoding questions show a word encoded using some consistent rule — often a fixed alphabet shift, a letter-to-number mapping, or a word-substitution code — and ask you to encode or decode a different word using the same rule.
Common patterns
- A fixed forward or backward alphabet shift applied to every letter
- A=1, B=2, ... letter-to-number substitution
- Word-substitution codes solved by comparing overlapping sentences
Worked example
Question: If CAT is written as ECV, how is DOG written?
Answer: FQI
Each letter shifts forward by 2; applying the same shift to DOG gives FQI.
How to approach Coding-Decoding
Identify the information given, test the simplest consistent rule, and verify that your rule explains every relevant part before answering.