In this letter analogy, HI is related to MD by a fixed alphabet shift. Using the same pattern of shifts, how should UV be coded?

Introduction / Context:
This question is a two letter coding analogy that checks your understanding of position based shifts in the alphabet. The given pair HI : MD contains the key to the pattern. Once you determine how H changes to M and how I changes to D, you must apply the same letter wise transformation to the pair UV to discover which coded pair among the options correctly completes the analogy.

Given Data / Assumptions:

We work with the standard alphabet, where A = 1, B = 2, ..., Z = 26.
The pair HI becomes MD under a particular transformation applied to each letter separately.
The second pair UV must be transformed by the same rule to form the answer.
The answer choices for the code of UV are YR, WS, ZQ and ER.
We assume no rearrangement of letter order, only position based shifts forward or backward.

Concept / Approach:
The strategy is to translate letters into numbers and inspect the change. For HI to become MD, we compare H with M and I with D. If we find constant differences or a clear pattern in how positions change, that rule should be repeated for U and V. When we compute positions, H is 8 and M is 13, while I is 9 and D is 4. So the first letter increases by 5 positions and the second letter decreases by 5 positions, wrapping around the alphabet if needed. This balanced plus and minus rule is the key to the analogy.

Step-by-Step Solution:
Step 1: Write down the positions of H and M. H is 8, M is 13, so the change is 8 to 13, an increase of 5. Step 2: Write the positions of I and D. I is 9, D is 4, so the change is 9 to 4, a decrease of 5. Step 3: Conclude the rule: first letter is shifted forward by 5 positions, second letter is shifted backward by 5 positions. Step 4: Now apply this rule to U and V. U is the 21st letter. Add 5 to get 26, which is Z. Step 5: V is the 22nd letter. Subtract 5 to get 17, which is Q. Step 6: Combine these new letters to get ZQ as the coded form of UV.

Verification / Alternative check:
It is good practice to check that the rule works cleanly with wrap around. For example, if the sum had exceeded 26, we would loop back from A. In this case, 21 plus 5 is exactly 26, so U maps directly to Z without wrapping further. For the second letter, 22 minus 5 is 17, giving Q. Now quickly verify the original mapping again: 8 plus 5 gives 13 (H to M) and 9 minus 5 gives 4 (I to D). This consistent application confirms that we have the correct transformation. Checking the answer choices shows that only ZQ fits this rule.

Why Other Options Are Wrong:
YR does not follow the plus five, minus five rule when you work forward from U and V. WS would give W as 23 and S as 19, but U to W is only plus two and V to S is minus three, which breaks the pattern. ER would imply U maps to E by wrapping backward and V maps to R, another completely different shift. None of these maintain the precise plus five for the first letter and minus five for the second letter established in the HI : MD example.

Common Pitfalls:
A frequent mistake is to assume a single shift direction for both letters and try to fit all changes as either plus or minus. Another pitfall is miscounting positions when moving across the alphabet, especially near the end of the sequence. To avoid errors, always write down the numeric positions and calculate differences carefully rather than relying on visual guesses. Recognising that many coding questions use symmetric patterns such as plus k and minus k can also help you quickly spot the correct logic in similar items.

Final Answer:
Using the rule “first letter plus five, second letter minus five”, UV is coded as ZQ, so ZQ is the correct answer.