Classification – Letter pairs: identify the odd one out using the rule “sum of alphabetical positions = 27.” Three pairs satisfy first+second = 27 (A=1 … Z=26); one pair does not. Which pair is different? Options: DW, LO, JR, HS.

Introduction / Context:
Complementary letter pairs often sum to a fixed constant (A+Z=27, B+Y=27, etc.). This is a common test in pair-classification problems.

Given Data / Assumptions:

• A=1 … Z=26; target sum=27.
• Pairs: DW, LO, JR, HS.

Concept / Approach:
Compute the sum of positions for each pair; the outlier will not total 27.

Step-by-Step Solution:
D(4)+W(23)=27 ✔L(12)+O(15)=27 ✔H(8)+S(19)=27 ✔J(10)+R(18)=28 ✖

Verification / Alternative check:
Check complements: D↔W, L↔O, H↔S are standard complement pairs; J↔Q would be 27, not J↔R.

Why Other Options Are Wrong:
DW, LO, HS: Each forms a valid 27-sum complementary pair.

Common Pitfalls:
Adding letter indices with off-by-one mistakes; ensure A=1 (not 0).

Final Answer:
JR