Which two letters will come in place of the question marks (?) in the given series?
B, A, D, B, H, C, ?, ?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → N, D
When the letters do not change in one steady way, split the series into the letters at odd places and the letters at even places; each part follows its own rule.
Odd places: B (2), D (4), H (8); the steps are \(+2, +4\), so the next step is \(+6\): \(8+6=14\), which is N
Even places: A, B, C; each is the next letter, so next is D
The seventh term is at an odd place and the eighth at an even place
So the two missing letters are N, D.