Classification – Odd one out (triplets with +2 then +3 and vowel center): Which set does not share the same internal pattern: MOR, GIL, SUX, ACF?

Introduction / Context:
These triplets share two layered properties in many exam keys: (1) letter steps of +2 then +3 (left→middle, middle→right), and (2) the middle letter being a vowel. Three triplets satisfy both; one fails the vowel condition despite matching the numeric steps. The outlier is the only set whose middle letter is a consonant.

Given Data / Assumptions:

• MOR → M(13)→O(15)=+2; O(15)→R(18)=+3; middle letter O is a vowel.
• GIL → G(7)→I(9)=+2; I(9)→L(12)=+3; middle letter I is a vowel.
• SUX → S(19)→U(21)=+2; U(21)→X(24)=+3; middle letter U is a vowel.
• ACF → A(1)→C(3)=+2; C(3)→F(6)=+3; middle letter C is a consonant.

Concept / Approach:
While all four meet the numeric +2,+3 progression, only one breaks the “vowel as the center” pattern. Reasoning questions often layer such dual cues to force careful checking beyond arithmetic alone.

Step-by-Step Solution:
1) Verify step sizes → all four pass.2) Check middle-letter vowel status → MOR/GIL/SUX pass; ACF fails.3) Therefore, ACF is the odd one out.

Verification / Alternative check:
Try the vocalic center test on a different set; you will see the same discriminator works reliably across many exam patterns.

Why Other Options Are Wrong:
They satisfy both numeric progression and vowel-center conditions.

Common Pitfalls:
Stopping after verifying only arithmetic steps and missing the layered vowel cue.

Final Answer:
ACF