In the following alphabet pattern reasoning question, four groups of three letters each are given: POR, MEF, TUD and STD. Three groups have their first two letters in consecutive alphabetical order, while one group has the consecutive letters in a different position. Select the odd letter group from the given alternatives.

Introduction / Context:
This question tests your ability to detect patterns in sequences of letters. You are given four three letter groups: POR, MEF, TUD and STD. In verbal reasoning, a common pattern involves consecutive letters of the English alphabet appearing in fixed positions (for example, as the first two letters or the last two letters). Here, three of the groups have their first two letters as consecutive neighbours in the alphabet, while one group has the consecutive pair in a different position. You must identify that differently structured group as the odd one out.

Given Data / Assumptions:

• Letter groups: POR, MEF, TUD and STD.
• Alphabet positions: A = 1, B = 2, ..., Z = 26.
• We pay attention to whether letters are consecutive and where that consecutiveness occurs in the group.
• Three groups have the first and second letters consecutive in the alphabet.
• Exactly one group places its consecutive pair in a different position.

Concept / Approach:
We examine each group to see which pair of letters is consecutive in the alphabet. In POR, TUD and STD, the first two letters form consecutive alphabet positions, though sometimes in reverse order. In MEF, however, the consecutive letters appear in the second and third positions, not in the first and second. The odd group is therefore the one that does not match the positional pattern shown by the other three groups.

Step-by-Step Solution:
Step 1: Analyse POR.P and O are the first two letters. In terms of positions, P = 16 and O = 15. They are consecutive letters in reverse order (16, 15). The third letter R = 18 is not adjacent to O.Step 2: Analyse TUD.T and U are the first two letters. T = 20 and U = 21, which are consecutive letters in forward order. D = 4 is separate.Step 3: Analyse STD.S and T are the first two letters. S = 19 and T = 20, again consecutive in forward order. D = 4 is not adjacent to T.Step 4: Analyse MEF.M and E are the first two letters. M = 13 and E = 5 and are not consecutive. However, E = 5 and F = 6 (second and third letters) are consecutive in forward order.Step 5: Identify the pattern and the odd group.In POR, TUD and STD, the first two letters form a consecutive pair. In MEF, the consecutive pair appears in the second and third positions, not in the first two. Therefore MEF is the odd letter group out.

Verification / Alternative check:
A quick verification method is to underline the consecutive letters in each group. For POR you underline P and O, for TUD you underline T and U, and for STD you underline S and T. In all three cases, the underline covers the first and second positions. For MEF, you underline E and F, which are the second and third letters. This simple visual check makes the difference in structure obvious and confirms that MEF does not match the layout that appears in the other three groups.

Why Other Options Are Wrong:
POR: Has P and O as the first two letters, which are consecutive, so it follows the main pattern.
TUD: Has T and U as the first two letters, which are consecutive in forward order, again fitting the pattern.
STD: Has S and T as the first two letters, which are also consecutive, so it is not the odd one.

Common Pitfalls:
Students sometimes only look for any two consecutive letters in each group and conclude that all four are similar. The key here is not just whether there is a consecutive pair, but where it is located within the group. Pattern questions often rely on the exact position of the pattern as much as the pattern itself. Paying attention to the positions of letters or digits is crucial for solving such questions accurately.

Final Answer:
The odd letter group is MEF, because it has its consecutive letters in the second and third positions, while in the other three groups the first and second letters are consecutive in the alphabet.