In the following question, each option shows a series of three English letters in increasing order. Select the group that does not follow the same spacing pattern as the others (odd letters).

Introduction / Context:
This letter series question checks how well the learner can observe and compare patterns in alphabetical sequences. Odd one out problems of this style are very common in reasoning tests, especially in sections dealing with sequences and series. The key idea is to notice the step size between letters in each option and find which one does not match the common rule.

Given Data / Assumptions:
- The options are ACE, FHJ, QTW, KMO, and PRT.
- Each group contains three letters in English alphabetical order, not jumbled words.
- We use standard positions where A is 1, B is 2, and so on up to Z as 26.
- Exactly one letter group does not maintain the same step size pattern as the other groups.

Concept / Approach:
In many exam problems, letter sequences are formed by skipping a fixed number of letters between consecutive characters. Here, we need to compute how many letters are skipped between the first and second letter and between the second and third letter in each group. If four groups show a step of plus 2 between letters, but one shows a different spacing, that one will be the odd one out.

Step-by-Step Solution:
Step 1: Consider ACE. The positions are A = 1, C = 3, E = 5. From A to C, the step is +2, and from C to E, the step is also +2.Step 2: Consider FHJ. The positions are F = 6, H = 8, J = 10. From F to H and from H to J, both steps are +2, so this matches ACE.Step 3: Consider KMO. The positions are K = 11, M = 13, O = 15. Again, both movements are +2, matching the same pattern.Step 4: Consider PRT. The positions are P = 16, R = 18, T = 20. This also follows a consistent +2 step pattern between consecutive letters.Step 5: Now consider QTW. The positions are Q = 17, T = 20, W = 23. From Q to T the step is +3, and from T to W the step is also +3, not +2.Step 6: Since ACE, FHJ, KMO, and PRT all use a step of +2, but QTW uses a step of +3, QTW is the group that does not follow the common pattern.

Verification / Alternative Check:
We can verify again by counting letters directly in the alphabet. For example, starting from A and moving two steps forward gives C, then another two steps gives E. The same behavior is seen with F to H to J, K to M to O, and P to R to T. In contrast, starting at Q, moving two steps forward would produce S, not T, so QST would follow the plus 2 pattern, but QTW moves three steps from Q to T and another three to W. This confirms that QTW does not belong with the other sequences and must be the odd one out.

Why Other Options Are Wrong:
ACE is not the odd one out because its letters are separated by a constant gap of two positions, matching the base pattern. FHJ also maintains the same gap and therefore fits neatly into the group. KMO continues this rule with a step of two between letters. PRT again follows the plus two pattern and is fully consistent with the majority. Since these four share the same type of regular spacing, none of them can be chosen as the odd one out.

Common Pitfalls:
Test takers sometimes look only at whether letters are in alphabetical order and overlook the size of the step between them. Another pitfall is to be distracted by the visual appearance of letters or to think that rare letters like Q and W must automatically be odd. The correct approach is always to compute the numerical differences between letter positions. That method avoids guesswork and makes series based odd one out questions much easier to solve accurately.

Final Answer:
QTW