if CLOCK is coded as DMPDL, then what will be the code for WATCH?

Appeared in: NORCET 9 Prelims-2025

Explanation

The problem uses a simple substitution cipher where each letter in the original word is replaced by the letter that immediately follows it in the alphabet.
This is also known as a Caesar cipher with a shift of +1.
Applying this +1 shift to 'CLOCK' gives 'DMPDL' (C→D, L→M, O→P, C→D, K→L).
Applying the same +1 shift to 'WATCH' gives 'XBUDI' (W→X, A→B, T→U, C→D, H→I).

Option B: This option incorrectly keeps the first letter 'W' unchanged instead of shifting it to 'X'. The rest of the letters are shifted correctly.
Option C: This option incorrectly shifts the last two letters. 'C' is shifted to 'E' (+2) and 'H' is shifted to 'J' (+2), which violates the consistent +1 shift pattern.
Option D: This option has multiple incorrect letters ('N', 'U', 'J', 'D') that do not follow the established +1 shift pattern. The coding is inconsistent and random compared to the logic derived from the example.

Visual 1: Infographic: An infographic illustrating the +1 alphabet shift cipher. It could show the alphabet in a line or circle with arrows pointing from each letter to the next (A→B, B→C, etc.) to visually represent the forward shift.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Logical Reasoning: Coding-Decoding by Letter Shifting as background academic context rather than a clinical decision trigger.
This question does not test clinical knowledge but assesses logical reasoning and pattern recognition skills.
These skills are crucial for nurses in clinical problem-solving, such as identifying trends in a patient's vital signs, interpreting lab results, and making quick, logical decisions under pressure.
What if the code for CLOCK was 'BNPBJ'? The pattern would be a -1 shift (C-1=B, L-1=K... wait, L-1 is K, not N). The pattern is C-1=B, L+2=N, O+1=P, C-1=B, K-1=J. This is a mixed pattern. You would need to find the logic for this new pattern to solve for WATCH.

How to Approach the Question

First, carefully examine the given example: 'CLOCK' is coded as 'DMPDL'.
Compare each letter of the original word with the corresponding letter in the code to find the pattern. (C -> D, L -> M, O -> P, C -> D, K -> L).
Identify the rule. In this case, you'll notice each letter is shifted one position forward in the English alphabet.
Apply this identified rule (+1 shift) to the word you need to code, 'WATCH'.
Systematically shift each letter: W -> X, A -> B, T -> U, C -> D, H -> I.
Combine the new letters to form the code 'XBUDI' and select the matching option.

Concept Tested & Keywords

QodrKdSaZbHp14n4Zmbo4K

Practise the full NORCET 9 Prelims-2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.