Classification – Odd one out (triplets with +3 then −2 pattern): Which triplet breaks the +3, then −2 letter-step rule: HKI, UXV, CFD, MQN?

Introduction / Context:
In many pattern sets, the first jump is a forward move of a fixed size and the second jump is a backward move of a different fixed size. Here, three triplets follow +3 then −2 (positions A=1 to Z=26). One triplet does not and is the outlier.

Given Data / Assumptions:

• HKI → H(8)→K(11)=+3; K(11)→I(9)=−2.
• UXV → U(21)→X(24)=+3; X(24)→V(22)=−2.
• CFD → C(3)→F(6)=+3; F(6)→D(4)=−2.
• MQN → M(13)→Q(17)=+4; Q(17)→N(14)=−3 (not +3 then −2).

Concept / Approach:
Compute the two gaps for each option and compare with the target signature (+3, −2). Any deviation in size identifies the odd one. MQN uses +4 then −3, so it breaks the rule.

Step-by-Step Solution:
1) Calculate both step sizes per triplet.2) Select the unique non-matching triplet: MQN.

Verification / Alternative check:
Reversing the order yields the inverse ( +2 then −3 ) for the valid sets; MQN still fails to align, confirming the mismatch.

Why Other Options Are Wrong:
HKI, UXV, CFD faithfully implement +3 then −2.

Common Pitfalls:
Confusing letter cases or reading left-to-right inconsistently. Stick to one direction for comparisons.

Final Answer:
MQN