Applications of Reasoning -- Coding-Decoding

Coding-decoding problems are a direct application of the logical reasoning you have already studied — they test your ability to spot a hidden rule or pattern that transforms one set of symbols into another. Instead of memorising arbitrary codes, the key is to think like a detective: look for the relationship between the given word and its code, then apply that same rule to the new word. Whether the code involves shifting letters by a fixed number of positions, reversing the order, or using a simple arithmetic operation on the alphabet positions $A=1, B=2, \dots, Z= …