In a certain code, CUP is written as XFK. How is DOOR written in that code?

💡 Solution & Explanation

Each letter is replaced by its opposite letter in the alphabet (A ↔ Z, B ↔ Y, C ↔ X, and so on). A letter and its opposite always add up to 27 in position: C (3) → X (24), U (21) → F (6), P (16) → K (11). For DOOR: D → W, O → L, O → L, R → I. So the code is WLLI.