Position-based letter shift rule: If “MOUSE” is coded as “PRUQC” by applying +3 to the first two letters, leaving the middle unchanged, and −2 to the last two letters, how is “SHIFT” written?

Introduction / Context:In many coding-decoding questions, a fixed positional rule (different shifts for different positions) is applied to each letter of a word. The example “MOUSE → PRUQC” hints at a specific positional transform rather than a single uniform Caesar shift. We must infer that transform and then encode “SHIFT”.

Given Data / Assumptions:

• Alphabet indexing assumed cyclic (after Z wraps to A).
• Example: MOUSE → PRUQC.
• Target: SHIFT → ?

Concept / Approach:Compare letters by position. For “MOUSE”: M→P (+3), O→R (+3), U→U (0), S→Q (−2), E→C (−2). This reveals a clean rule for a 5-letter word: +3 on the first two letters, keep the third unchanged, −2 on the last two letters.

Step-by-Step Solution:

Verification / Alternative check:If we attempted a single Caesar shift, MOUSE would not map to PRUQC because U would not remain U while M and O both increase. The positional rule uniquely explains all five mapped letters.

Why Other Options Are Wrong:

• VJIDR / VIKRD / RKIVD: Each violates the derived position-wise rule at one or more positions (wrong shift for H or incorrect treatment of the middle letter).
• None of these: Incorrect because VKIDR fits exactly.

Common Pitfalls:Assuming a uniform shift for the whole word or overlooking that U remained unchanged in the exemplar, which is the key to spotting the middle-letter rule.

Final Answer:VKIDR