Coding-decoding is 3–5 marks every paper. Master these 7 patterns and you'll decode any question in under 20 seconds.
3–5 questions every paper, all formula-based. Once you spot the pattern, it's a 15-second solve.
Each letter shifts by n positions. Example: CAT (+2) = ECW. Trick: Memorise A=1, B=2 ... Z=26. Add/subtract directly.
A↔Z, B↔Y, C↔X. Each letter i maps to 27−i.
Reverse the word, then shift each letter by ±n.
Each letter replaced by its position number. CAT = 3-1-20.
First letter as position + word length, etc. Identify the rule from the example.
Each letter or concept → a fixed symbol. Build the mapping table from the example.
Word-level coding: "sky is blue" = 472, "blue is far" = 932. Find shared word ↔ shared digit.
1. Decode the example first. Don't try to guess — verify the pattern with the given pair. 2. Apply the verified rule to the target word. 3. Cross-check with the options — if your answer isn't in the options, your pattern is wrong.
Different shift per letter (A=+1, B=+2, ...) — looks like uniform shift until you check Mixed coding (first half +n, second half −n) Letter-pair coding (treat 2 letters as a unit)
Use the EJOTY rule: E=5, J=10, O=15, T=20, Y=25. From any of these, count up or down to find a target letter fast.
Day 1–3: Master each of the 7 patterns with 5 examples Day 4–7: Mixed practice — 30 questions/day from SSCIntel Week 2: Time-boxed drills (15 seconds/question)
Within 2 weeks, coding-decoding becomes reflex.
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