Which letter will replace the question mark (?) in the following series?
C, E, I, O, W, ?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → G
Write each letter as its place in the alphabet and look at the gaps between neighbours; after Z the count continues from A.
C (3) to E (5) is 2 places, E (5) to I (9) is 4 places, I (9) to O (15) is 6 places, and O (15) to W (23) is 8 places
The gaps grow by 2, so the next gap is 10
10 places ahead of W: X, Y, Z take 3 places, and 7 more from A reach G
So the missing letter is G.