Logical Reasoning: Coding-Decoding

Concept Explanation

Coding-decoding questions give a word or number code and ask you to apply the same rule to another word. The rule is always consistent for every letter in the example pair.

Common rules in placement exams

• Letter shift: every letter moved +1, +2, or −1 (CAT → DBU).
• Alphabet position: A=1 … Z=26 — sum, concatenate, or reverse alphabet (A↔Z).
• Rearrangement: reverse the word, sort letters A–Z, or swap adjacent pairs.
• Letter-wise math: alternate +1 and −2 on successive letters (VISION → WGTGPL).
• Mixed: sum of positions plus letter count, or square of word length.

How to solve fast

1. Compare the word and its code letter by letter when lengths match.
2. If the code is numeric, try position sums, concatenation, or digit swaps on one example first.
3. Write the rule in one line, then apply it to every letter of the new word.
4. Check vowels separately when consonants alone seem to change.