Which letter-cluster will replace the question mark (?) to complete the given series? CQJG, ERMJ, ?, ITSP, KUVS

Correct — D. Split the clusters into four columns and read each column downwards.

Rule: column 1 steps +2, column 2 steps +1, column 3 steps +3, column 4 steps +3.

Column 1: C(3), E(5), G(7), I(9), K(11)
Column 2: Q(17), R(18), S(19), T(20), U(21)
Column 3: J(10), M(13), P(16), S(19), V(22)
Column 4: G(7), J(10), M(13), P(16), S(19)

The missing cluster is GSPM — option (d).

Why the others are wrong

• (a)
  GSQM — Column 3 runs J, M, ?, S, V in steps of three, so the third letter is P. This option offers Q, which would make one step a four and the next a three.
• (b)
  GRPM — Column 2 is a plain +1 ladder, Q, R, ?, T, U, so the third letter is S. This option repeats R, which already stands in the second cluster.
• (c)
  GTPM — On the same +1 ladder, T is the fourth rung and belongs to ITSP. This option pulls T forward one place into the third cluster.

A letter-cluster series is four independent series printed side by side, so break it into columns before doing anything else.

Convert each column into numbers with A = 1, work out its step, and convert back only at the end. Here the steps are 2, 1, 3 and 3 — different in every column, which is why reading the clusters left to right shows no pattern at all.

The blank sits in the middle of this series, so every column can be checked from both sides: G must be two past E and two short of I, and it is.

Key facts

• The four columns advance by 2, 1, 3 and 3 letters per step.
• Column 1 reads C, E, G, I, K, which is every second letter starting at C.
• Column 4 reads G, J, M, P, S, three letters apart throughout.

Common traps

• Assuming all four columns share one step because the first two clusters look regular
• Measuring a step from the wrong neighbour when the blank sits in the middle
• Slipping between S and T in column 2, where the ladder is a single letter wide

No directly related past PYQ was found.