Which of the following letters will replace the question mark (?) and complete the following letter series? F, D, J, B, N, Z, ?
Understanding the Letter Series Pattern
The core task is to identify the missing letter in the sequence: F, D, J, B, N, Z, ?. This requires finding the underlying pattern or rule that governs the series.
Analyzing the Series Sequence
First, let's represent each letter by its corresponding position in the English alphabet (A=1, B=2, ..., Z=26):
- F corresponds to $6$
- D corresponds to $4$
- J corresponds to $10$
- B corresponds to $2$
- N corresponds to $14$
- Z corresponds to $26$
The series in numerical form is: $6, 4, 10, 2, 14, 26, ?$
Identifying the Interleaved Patterns
By examining the numerical sequence, we can observe that it seems to be composed of two separate, interwoven sequences:
Sequence 1 (Letters at odd positions): F, J, N, ?
Sequence 2 (Letters at even positions): D, B, Z, ...
We need to find the letter for the 7th position, which belongs to Sequence 1.
Step-by-Step Solution for Sequence 1
Let's focus on the first sequence: F, J, N, ?
The positions are: $6, 10, 14, ?$
Now, let's find the difference between consecutive terms in this sequence:
- Position of J ($10$) minus Position of F ($6$) equals $10 - 6 = 4$.
- Position of N ($14$) minus Position of J ($10$) equals $14 - 10 = 4$.
The pattern for Sequence 1 is consistently adding $4$ to the position number of the previous letter.
To find the next letter (the 7th term overall), we apply this pattern to the last known term of Sequence 1 (N):
Position = Position of N + $4$
Position = $14 + 4 = 18$
The letter corresponding to the position $18$ in the alphabet is R.
Step-by-Step Solution for Sequence 2 (for completeness)
Let's examine the second sequence: D, B, Z
The positions are: $4, 2, 26$
Calculate the difference between consecutive terms:
- Position of B ($2$) minus Position of D ($4$) equals $2 - 4 = -2$.
- To find the next term after B ($2$), we subtract $2$. $2 - 2 = 0$. Since the alphabet wraps around after Z ($26$), the position $0$ corresponds to Z ($26$). So, the difference from B ($2$) to Z ($26$) is effectively $-2$ (with wrap-around).
The pattern for Sequence 2 is subtracting $2$ from the position number (using wrap-around).
Conclusion
The question mark is at the 7th position, which is part of the first sequence (F, J, N, ?). Following the pattern of adding $4$, the missing letter is R.
| Term | Letter | Position (Alphabet) | Sequence Type | Operation | Resulting Letter | Resulting Position |
| 1 | F | $6$ | 1 | F | $6$ | |
| 2 | D | $4$ | 2 | D | $4$ | |
| 3 | J | $10$ | 1 | +4 (from F) | J | $10$ |
| 4 | B | $2$ | 2 | -2 (wrap) (from D) | B | $2$ |
| 5 | N | $14$ | 1 | +4 (from J) | N | $14$ |
| 6 | Z | $26$ | 2 | -2 (wrap) (from B) | Z | $26$ |
| 7 | ? | 1 | +4 (from N) | R | $18$ |
Therefore, the letter that correctly replaces the question mark (?) in the series is R.
Important Questions from Alphabet Series
Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
G _ C T _ X _ T G X _ T _ X C T G _ C T
Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
Q _ P _ M _ A _ T _ Q A _ T M
Select the combination of letters that when sequentially placed in the blanks of the given series will complete the series.
r _ x l _ q _ _ x _ p q _ e _ l p _
Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
BKR, DNV, FQZ, ?, JWH
Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
AU, BO, CI, DE, ?
