Which letter cluster will replace the question mark (?) in the following series?
SOK, VLN, ?, BFT, ECW
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → YIQ
Each position of the cluster is checked on its own, using places in the alphabet; when the count goes past Z, it continues from A.
First letters S (19), V (22): 3 places ahead, so the missing letter is \(22+3=25\), Y; 3 places ahead of Y are Z, A, B, which matches B in the fourth term, and B (2) to E (5) is again 3 places
Second letters O (15), L (12): 3 places back, so the missing letter is \(12-3=9\), I; then \(9-3=6\) gives F and \(6-3=3\) gives C, which match the last two terms
Third letters K (11), N (14): 3 places ahead, so the missing letter is \(14+3=17\), Q; then \(17+3=20\) gives T and \(20+3=23\) gives W, which match the last two terms
So the missing cluster is YIQ.