In the series of letters B, F, J, N, R, V, Z, D, H, L, ? Which of the following letters will replace the question mark ?

The correct answer is C, P.

The series moves forward by a fixed step of four letters in the alphabet. B(2) to F(6) to J(10) to N(14) to R(18) to V(22) to Z(26). After Z, the count wraps around past the end of the alphabet: 26 + 4 = 30, which is 4 again, so the next letter is D. The pattern then continues as D to H to L, and the next step from L(12) gives P(16).

Why the other options fail:

• A) M is position 13, a step of one from L. That breaks the fixed gap of four.
• B) O is position 15, a step of three from L. Also wrong.
• D) T is position 20, which would need a step of eight from L. Wrong.

The core concept is letter-position series with a constant alphabetical gap, including wrap-around. This is a staple of UPPSC reasoning and of the general mental-ability section, where speed comes from converting letters to numbers quickly.

Trap: aspirants stop the series at Z and assume it must end there, or they count the gap from the last letter of the visible series instead of checking the step from every term.