Which of the following terms will replace the question mark (?) in the given series? AWSO, KGCY, UQMI, EAWS, ?

Correct — C. Write the alphabet position under every letter, A = 1 to Z = 26.

Rule: each letter of a term climbs +10 to give the next term, wrapping by subtracting 26 past Z.

AWSO = 1, 23, 19, 15
+10 each = 11, 7, 3, 25 = KGCY (23 + 10 = 33 - 26 = 7)

KGCY = 11, 7, 3, 25 gives 21, 17, 13, 9 = UQMI
UQMI = 21, 17, 13, 9 gives 5, 1, 23, 19 = EAWS

EAWS = 5, 1, 23, 19
+10 each = 15, 11, 7, 3 = OKGC -> option (c)

Why the others are wrong

• (a)
  WAEI — WAEI fails at the first letter: E + 10 = O, not W. Its own letters run 23, 1, 5, 9, an ascending +4 chain that belongs to no part of this series.
• (b)
  ZWTQ — ZWTQ runs 26, 23, 20, 17 — a -3 gap inside the term. Every term here steps -4 inside itself, and its first letter must be E + 10 = O.
• (d)
  OGKH — OGKH opens correctly with O, then swaps the middle pair and ends in H. The required term is O, K, G, C, because A + 10 = K, W + 10 = G and S + 10 = C.

A letter series like this one is arithmetic wearing an alphabet costume. Write the position of every letter underneath it and the pattern usually appears at once.

Two patterns run here at the same time. Inside each term the letters fall by 4. Between terms every letter climbs by 10.

Either one alone reaches the answer. Using both is a free check, and when two options open with the same letter, that check is what separates them.

Key facts

• Positions run A = 1 to Z = 26, and a step past Z wraps by subtracting 26.
• Each given term falls by 4 inside itself: A W S O is 1, 23, 19, 15.
• The step from one term to the next is +10 on all four letters.
• The full series is AWSO, KGCY, UQMI, EAWS, OKGC.

Common traps

• Forgetting to subtract 26 after passing Z, so 33 is written as a letter that does not exist.
• Checking the first letters of the terms only and never testing letters 2 to 4.
• Stopping at the option that starts with the right letter.

No directly related past PYQ was found.