In the reverse triplet alphabet series ZYX, VUT, QPO, MLK, HGF, which group of three letters should come next to continue the pattern?

Introduction / Context:
This problem involves groups of three letters written in reverse alphabetical order. The task is to detect how each triplet relates to the next one in the sequence. Such patterns are typical in reasoning and alphabet test questions, where you must track changes not only inside each group but also from one group to another. Understanding this pattern helps improve your ability to decode letter based sequences under time pressure in competitive exams.

Given Data / Assumptions:
- The given series is: ZYX, VUT, QPO, MLK, HGF, ? - Each term is a block of three consecutive letters written in reverse order. - We assume the pattern is consistent across all given terms. - Alphabet positions are used for analysis: A = 1, B = 2, ..., Z = 26.

Concept / Approach:
We handle two levels of pattern. First, we confirm that each triplet is formed by three consecutive letters in reverse alphabetical order. Second, we examine how the starting letter of each triplet moves through the alphabet from one term to the next. If the starting letters follow a regular numerical pattern, we can extend that pattern to find the next starting letter, and then form the full triplet in reverse order. This approach is systematic and reduces the chance of guessing wrongly among similar looking options.

Step-by-Step Solution:
Step 1: Write down each triplet with letter positions. ZYX: Z (26), Y (25), X (24). VUT: V (22), U (21), T (20). QPO: Q (17), P (16), O (15). MLK: M (13), L (12), K (11). HGF: H (8), G (7), F (6). Step 2: Look at the first letters: Z, V, Q, M, H. Positions: 26, 22, 17, 13, 8. Step 3: Compute differences: 26 to 22 is -4, 22 to 17 is -5, 17 to 13 is -4, 13 to 8 is -5. So the pattern alternates between -4 and -5. Step 4: Continue this alternating pattern to find the next starting position. We ended on 8 (H) with a difference of -5, so the next difference is -4. 8 - 4 = 4, which corresponds to D. Step 5: Form the next reverse triplet starting from D. Three consecutive letters backward from D are D, C, B, giving DCB.

Verification / Alternative check:
We can also think in terms of underlying forward triplets. ZYX is reverse of XYZ, VUT is reverse of TUV, and so on. Each block in forward order starts several letters earlier than the previous one, matching the numeric pattern already detected. When we use DCB, we maintain the rule that each group is a descending run of three letters, and that the gap between starting letters continues the -4, -5 alternation. No other listed option, if inserted, preserves both of these conditions at the same time.

Why Other Options Are Wrong:
B) CBA shifts the start position by -5 from H, which would break the alternating -4, -5 pattern sequence. C) BCD is not a reverse ordered triplet and therefore violates the internal structure of each term. D) EDC starts at E (5), which does not follow the -4, -5 alternating pattern from the previous starting letter H (8).

Common Pitfalls:
A common mistake is to look only at the last few letters instead of analysing the series from the beginning. Another issue is to check only whether each option itself is a descending triplet, without verifying if the jump from the previous term fits the overall numeric pattern. Candidates sometimes choose CBA simply because it is another reverse block that looks similar. However, exam style questions require a consistent rule across all terms, not just visual similarity. Always check both the internal structure of each block and the way starting letters progress through the alphabet.

Final Answer:
The next triplet in the reverse alphabet series ZYX, VUT, QPO, MLK, HGF, ? is DCB.