Logic Puzzles: Code-Breaking

Methods in this video

Tap a time to jump to where the video teaches that method.

1. 1

   Same code, swap a letter

   ▶ 0:44

   When to use it: One digit or key stands for several letters, and the question asks which decoded word is uncertain, or which word has the same code.

   • One code can stand for several letters, so a decoded word might be wrong.
   • Line up the letters that share a code: ten to a row, one digit to a column.
   • Swap one letter in each word and see if it is still a real word.
   • The word that gives a second real word is the uncertain one.
2. 2

   No code book? Look for what matches

   ▶ 2:26

   When to use it: The question gives only a few examples, or never says what the symbols mean, and asks which word the symbols spell or what could go in the box.

   • The same letter is always the same symbol, so you never need to know what a symbol means.
   • If a known letter's symbol isn't there, cross out options with that letter.
   • Repeated letters show as repeated symbols. All different symbols means no repeated letters.
   • Same symbol, same feature. No shared symbol, no shared feature.