Shifted, then reversed — Coding & Decoding Aptitude Question
Shifted, then reversed: If BOOK is coded as LPPC, how is PEN coded? Answer and worked solution on CodeKairo.
- Topic: Coding & Decoding
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 75 seconds
Question
If BOOK is coded as LPPC, how is PEN coded?
Options
- QFP
- OFQ
- QFO
- OQF
Show the answer and the worked solution
Correct answer: B. OFQ
Worked solution
- Read the code backwards: LPPC → CPPL.
- Against BOOK that is B→C, O→P, O→P, K→L — a shift of +1 on every letter.
- So the rule is: shift each letter forward by one, then reverse the word.
- PEN shifted by one is QFO; reversed, that is OFQ.
Answer: OFQ.
The idea
When no constant shift matches, test the code against the reversed word before trying anything more elaborate. Shift-then-reverse and reverse-then-shift are the two commonest two-step codes, and reading the given code backwards tells you which within seconds.
Shortcut. The code's first letter is the word's last letter + 1: N → O leaves OFQ and OQF, and the middle E → F picks OFQ.
Common trap. "QFO" — shifting each letter but forgetting to reverse; BOOK's code LPPC reads CPPL backwards, so the reversal is part of the rule.