Four letter-clusters have been given out of which three are alike in some manner and one is different. Select the one that is different. Note: The odd one out is not based on the number of consonants/vowels or their position in the letter cluster

Correct — C. Rule: first letter −3, then +5.

GDI: G −3 = D, D +5 = I
XUZ: X −3 = U, U +5 = Z
SPU: S −3 = P, P +5 = U

LKP fails the first step. L −3 would be I, but the cluster shows K, which is L −1. Its second step still fits, since K +5 = P.

Three clusters carry (−3, +5) and one carries (−1, +5), so option (c) is the different one.

Why the others are wrong

• (a)
  GDI — G to D is −3 and D to I is +5, the pattern two other clusters also follow, so GDI belongs to the group.
• (b)
  XUZ — X to U is −3 and U to Z is +5. The letters sit high in the alphabet but the gaps are identical to GDI's.
• (d)
  SPU — S to P is −3 and P to U is +5, the same structure again, so SPU cannot be the odd cluster.

An odd-one-out on letter clusters is a gap question. Write the alphabet positions under each cluster and compare the two internal differences rather than the letters themselves.

Here the gaps are (−3, +5) three times and (−1, +5) once, so the first gap does all the work.

The note attached to the question — that the answer does not rest on vowels, consonants or their placement — is the setter telling you the basis is arithmetic. Take it at face value and skip the vowel count.

Key facts

• G(7) D(4) I(9), X(24) U(21) Z(26) and S(19) P(16) U(21) all show gaps of −3 then +5.
• L(12) K(11) P(16) shows gaps of −1 then +5.
• The question's own note rules out vowel and consonant counting as the intended basis.

Common traps

• Checking only the second gap, which is +5 in every cluster and separates nothing
• Counting backwards from Z on late letters such as X and U
• Hunting for a vowel pattern the question has already ruled out

No directly related past PYQ was found.