In this letter-classification odd-man-out question, select the odd group of letters from the given alternatives.

Introduction / Context:
This question is a classic letter-series odd-man-out item from reasoning and aptitude tests. Each option is a group of three letters. Typically, such letter groups follow a fixed pattern based on positions of letters in the English alphabet. Three options follow a similar positional pattern, and one breaks that pattern. Your task is to detect the pattern and identify the group that does not fit.

Given Data / Assumptions:

• Options: FLR, KQW, PIB and CIO.
• We assume the standard English alphabet with positions A = 1 to Z = 26.
• We look for numerical relationships among the positions of the three letters in each group.

Concept / Approach:
In letter classification questions, a common pattern is a fixed difference between consecutive letters in each group. For example, letters may be spaced by plus 2, plus 3 or plus 6 positions. To apply this approach, we convert each letter into its alphabet position and then study the jumps from first to second and from second to third letters. The group that does not follow the shared difference rule will be the odd-man-out.

Step-by-Step Solution:
Step 1: Write the alphabet positions. F = 6, L = 12, R = 18, K = 11, Q = 17, W = 23, P = 16, I = 9, B = 2, C = 3, I = 9 and O = 15. Step 2: Analyse FLR. The differences are L - F = 12 - 6 = 6 and R - L = 18 - 12 = 6. So in FLR, consecutive letters increase by 6 positions each time. Step 3: Analyse KQW. The differences are Q - K = 17 - 11 = 6 and W - Q = 23 - 17 = 6. Again we have increases of 6 and 6, matching the same pattern. Step 4: Analyse CIO. The differences are I - C = 9 - 3 = 6 and O - I = 15 - 9 = 6. Once more, both jumps are plus 6, so CIO also follows the same rule. Step 5: Analyse PIB. The positions are P = 16, I = 9 and B = 2. Now the differences are I - P = 9 - 16 = -7 and B - I = 2 - 9 = -7. In PIB, both jumps are minus 7, that is, letters move backward in the alphabet instead of forward by 6. Step 6: Compare the patterns. FLR, KQW and CIO have a consistent pattern of +6 and +6, while PIB has a pattern of -7 and -7. PIB clearly does not follow the same forward spacing rule and is therefore the odd group.

Verification / Alternative check:
We can verify our conclusion by checking if any other simple rule could make PIB similar to the others, such as equal absolute difference ignoring direction. However, the others all move forward, not backward, and their absolute difference is 6, not 7. No alternative symmetric rule unites PIB with the other three without breaking their clean +6 structure. Thus, identifying PIB as the odd one out is consistent and logically sound.

Why Other Options Are Wrong:
FLR is not odd because its letters progress forward by 6 positions each time and match the pattern. KQW also follows +6 and +6, so it is part of the majority group. CIO satisfies the same rule and is therefore similar. PIB alone uses backward jumps of -7, which makes it different from all the others, so the other three cannot be the answer.

Common Pitfalls:
Students sometimes only look at the first and third letter and try to guess a pattern based on the overall span, ignoring the second letter. Others may assume that any group with reversed direction is acceptable, without checking for consistency across options. In classification questions, it is important to confirm that a single rule applies to three options and fails for exactly one option. Always compute the numerical differences rather than relying purely on visual guesswork.

Final Answer:
The odd group of letters is PIB, because in this group the letters move backward by 7 positions, whereas in all the other groups the letters move forward by 6 positions each time.