Logic Puzzles: Codes and Ciphers

Methods in this video

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1. 1

   Don't decode: encode the options

   ▶ 0:51

   When to use it: The question gives a rule or a code table, plus a long coded string or a table of replies, and asks which word or message it is. The options are whole words. The code has no gaps, or one code letter could mean two things.

   • Word to code is one road. Code to word is many roads. So start from the options.
   • See where the options differ and start checking there.
   • One wrong letter crosses the option out. When one is left, stop.
   • With no gaps, don't pick a word because its start fits: encode the whole word.
   • A reply table is a code too: cross out letters marked with a minus first.