Select the letter cluster that can replace the question mark (?) in the following series.
WTX, ZWA, CZD, ?, IFJ
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → FCG
In a letter-cluster series, each position of the cluster follows its own rule, so each position is checked separately using the place of the letter in the alphabet. The count continues from A after Z and from Z before A.
First letters W (23), Z (26), C (3): 3 places ahead each time, so the missing letter is \(3+3=6\), that is F; then \(6+3=9\) gives I, which matches the given letter
Second letters T (20), W (23), Z (26): 3 places ahead each time, so the missing letter is \(26+3=29\), and \(29-26=3\), that is C; then \(3+3=6\) gives F, which matches the given letter
Third letters X (24), A (1), D (4): 3 places ahead each time, so the missing letter is \(4+3=7\), that is G; then \(7+3=10\) gives J, which matches the given letter
So the missing cluster is FCG.