In this alphabet pair odd-man-out question, four pairs are given: KP, MN, HR and GT. For three of these pairs, the sum of the alphabetical positions of the two letters is 27, while in one pair the sum is different. Which option represents the odd pair based on this positional sum rule?

Introduction / Context:
This question is an alphabet-based odd-man-out problem. The pairs given in the stem are KP, MN, HR and GT, mapped to options A, B, C and D. Such questions often involve the numerical positions of letters in the English alphabet (A=1, B=2 and so on). Here, three of the pairs have a constant sum of positions, whereas one pair has a different total. The goal is to find the pair whose positional sum does not match that of the others.

Given Data / Assumptions:
Option A represents KP.
Option B represents MN.
Option C represents HR.
Option D represents GT.
Alphabet positions: A=1, B=2, ..., Z=26.
In three pairs, the sum of the positions of the two letters is 27.
One pair has a sum that is not equal to 27 and is therefore the odd one out.

Concept / Approach:
The concept is to convert letters to their numeric positions and compute the sum for each pair. If three sums are equal (here, 27) and one sum is different, the pair with the different sum is the odd pair. This method is straightforward and commonly used in alphabet reasoning questions. It helps you identify hidden numerical patterns behind letter combinations.

Step-by-Step Solution:
Step 1: For KP, K is the 11th letter and P is the 16th letter. Sum = 11 + 16 = 27. Step 2: For MN, M is the 13th letter and N is the 14th letter. Sum = 13 + 14 = 27. Step 3: For GT, G is the 7th letter and T is the 20th letter. Sum = 7 + 20 = 27. Step 4: For HR, H is the 8th letter and R is the 18th letter. Sum = 8 + 18 = 26. Step 5: Observe that three sums are 27 (KP, MN, GT), while HR has a sum of 26, which is different. Step 6: Conclude that the pair represented by option C (HR) is the odd one out.
Verification / Alternative check:
To verify, note that pairs whose positions add to 27 may be viewed as forming a near-symmetric pattern, since 27 is one more than 26, the total number of letters. KP, MN and GT all satisfy this special sum. HR, with a sum of 26, breaks this consistency. Rechecking the numeric positions (K=11, P=16, M=13, N=14, G=7, T=20, H=8, R=18) confirms that the calculations are correct and that HR is structurally different from the rest.

Why Other Options Are Wrong:
Option A (KP) has a positional sum of 27 and fits with options B and D in the main pattern.
Option B (MN) also sums to 27 and belongs to the same group as KP and GT.
Option D (GT) again sums to 27, so it is consistent with the pattern shared by KP and MN.
Option C (HR) alone has a sum of 26, making it different and therefore the correct odd-man-out choice.

Common Pitfalls:
A common mistake is to miscount the position of letters like K, M or R, which can distort the sums. Another pitfall is to look at the differences between letters instead of their sums, which does not reveal a clear and consistent pattern here. In exam situations, it is useful to confirm both the numeric positions and the addition to avoid arithmetic slips. Once you see that three pairs share the same total and one does not, the correct answer becomes obvious.

Final Answer:
The letter pair whose positional sum is different and is therefore the odd one out is HR, represented by option C.