Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which letter-cluster pair DOES NOT belong to that group? (Note: The odd one out is not based on the number of consonants/vowels or their position in the letter cluster)

Question

Prepp Team · Accepted Answer

Understanding Letter Cluster Pairs Reasoning

The question asks us to identify which pair of letter clusters does not follow a specific pattern related to the English alphabetical order. Three out of the four options will share a common logical relationship, while one will be the outlier.

Analyzing Letter Cluster Pairs

First, let's assign numerical values to each letter based on its position in the English alphabet (A=1, B=2, ..., Z=26).

Option	Letter Cluster Pair	Letters	Numerical Positions
1	PK - MJ	P, K, M, J	P(16), K(11), M(13), J(10)
2	NO - IJ	N, O, I, J	N(14), O(15), I(9), J(10)
3	FG - AB	F, G, A, B	F(6), G(7), A(1), B(2)
4	JK - EF	J, K, E, F	J(10), K(11), E(5), F(6)

Identifying the Pattern

We need to find a consistent relationship between the first cluster (e.g., PK) and the second cluster (e.g., MJ) within each option. Let's examine the difference in alphabetical positions between the corresponding letters:

Option 2: NO - IJ

First letter comparison: N (14) and I (9). The difference is $9 - 14 = -5$.
Second letter comparison: O (15) and J (10). The difference is $10 - 15 = -5$.
Observation: Both pairs have the same difference (-5).

Option 3: FG - AB

First letter comparison: F (6) and A (1). The difference is $1 - 6 = -5$.
Second letter comparison: G (7) and B (2). The difference is $2 - 7 = -5$.
Observation: Both pairs have the same difference (-5).

Option 4: JK - EF

First letter comparison: J (10) and E (5). The difference is $5 - 10 = -5$.
Second letter comparison: K (11) and F (6). The difference is $6 - 11 = -5$.
Observation: Both pairs have the same difference (-5).

Option 1: PK - MJ

First letter comparison: P (16) and M (13). The difference is $13 - 16 = -3$.
Second letter comparison: K (11) and J (10). The difference is $10 - 11 = -1$.
Observation: The differences (-3 and -1) are not the same.

Conclusion

The pattern observed in options 2, 3, and 4 is that the alphabetical difference between the first letter of the first cluster and the first letter of the second cluster is consistently -5, and the alphabetical difference between the second letter of the first cluster and the second letter of the second cluster is also consistently -5.

Option 1 (PK - MJ) does not follow this pattern because the differences are -3 and -1, which are not equal. Therefore, PK - MJ is the letter-cluster pair that does not belong to the group.