In the following letter analogy, CDE is related to XWV in a particular way. Using the same pattern, which group of letters should complete the analogy CDE : XWV :: ? : QPO?

Introduction / Context:
This analogy is based on a mirror like relationship in the alphabet, where pairs of letters are chosen such that their positions add up to a constant value. In the pair CDE : XWV, each letter in the first group is matched with a letter in the second group so that their positions in the alphabet sum to 27. We must find a group that has the same mirror relationship with QPO. This tests your understanding of symmetric positions in the alphabet.

Given Data / Assumptions:
First pair: CDE : XWV. Second pair: ? : QPO. All letters are capital English letters. The mapping is assumed to be letter to letter, maintaining order within each group.

Concept / Approach:
In an alphabet mirror pattern, letters are paired so that the sum of their positions is 27. For example, A (1) is paired with Z (26), B (2) with Y (25), and so on. When C (3) is paired with X (24), their positions add to 27. The idea is to check whether CDE and XWV fit this mirror rule. If they do, we apply the same rule to determine which group must mirror QPO in the same way.

Step-by-Step Solution:
Step 1: Write positions for CDE and XWV. C = 3, D = 4, E = 5. X = 24, W = 23, V = 22. Step 2: Check sums of corresponding positions. 3 + 24 = 27. 4 + 23 = 27. 5 + 22 = 27. So C pairs with X, D with W, and E with V under the mirror rule. Step 3: Apply the same mirror rule to QPO. Q = 17. The letter that pairs with Q must have position 27 - 17 = 10, which is J. P = 16. The letter that pairs with P must have position 27 - 16 = 11, which is K. O = 15. The letter that pairs with O must have position 27 - 15 = 12, which is L. Therefore, the required group is JKL.

Verification / Alternative check:
We can verify the pattern by adding positions of JKL and QPO. J (10) plus Q (17) equals 27, K (11) plus P (16) equals 27, and L (12) plus O (15) also equals 27. This confirms that JKL is the exact mirror of QPO under the same rule that connects CDE and XWV. No other option will satisfy this precise and symmetric mapping for all three letters.

Why Other Options Are Wrong:
KLM, GHI, ABC, and RST do not yield sums of 27 when paired with QPO letter by letter, so they do not satisfy the mirror relationship. Some of these options represent simple alphabetical runs but ignore the symmetric pairing structure demonstrated by CDE and XWV.

Common Pitfalls:
A common error is to notice only that CDE and XWV move in opposite directions through the alphabet and then guess another group that also appears reversed, without checking exact numeric positions. In mirror type analogies, you must verify the constant sum pattern for each pair of letters. Systematically adding positions helps you avoid misleading visual patterns and ensures that the chosen group truly preserves the underlying rule.

Final Answer:
The group of letters that correctly completes the analogy is JKL.