Coding and decoding involve transforming letters, numbers, or symbols based on specific rules or patterns. The goal is to identify the logic behind the transformation to encode or decode information effectively. This concept is widely used in reasoning problems, cryptography, and data encoding.

Types of Coding and Decoding

1. Letter Shifting: Each letter in a word is shifted by a fixed number of positions in the alphabet. For example, if "EARTH" is coded as "FCUXM," each letter is shifted by +1.

2. Reverse Order: The letters of a word are reversed. For instance, "COMPUTER" becomes "PMOCRETU."

3. Alphabet Position: Letters are replaced by their positions in the alphabet. For example, "HELLO" is coded as 8 5 12 12 15, where H=8, E=5, etc.

4. Summation of Positions: The sum of the alphabet positions of letters in a word is used. For example, "NEWYORK" is coded as 111 because the sum of its letters' positions is 111.

5. Numeric Substitution: Letters are replaced with specific numbers based on a predefined rule. For example, "BOMB" is coded as 5745, where each letter corresponds to a specific number.