To determine the missing letter in the sequence, let's examine the pattern formed by the given letters in the 3x3 grid:

H D A
N J ?
V N M

We'll analyze the pattern by rows, columns, and diagonals to see if there is a discernible logic to the arrangement of letters.

1. First Column: H, N, V

2. Second Column: D, J, N

3. Third Column: A, ?, M

4. First Row: H, D, A

5. Second Row: N, J, ?

6. Third Row: V, N, M

Examining Columns

First Column:

• H, N, V
  • Alphabetically, they are: H (8), N (14), V (22)
  • The differences: N - H = 6, V - N = 8
  • This doesn't reveal a simple pattern.

Second Column:

• D, J, N
  • Alphabetically, they are: D (4), J (10), N (14)
  • The differences: J - D = 6, N - J = 4
  • This also doesn't reveal a simple pattern.

Third Column:

• A, ?, M
  • Alphabetically, they are: A (1), ?, M (13)
  • The differences aren't clear without the middle letter.

Examining Rows

First Row:

• H, D, A
  • Alphabetically, they are: H (8), D (4), A (1)
  • The differences: D - H = -4, A - D = -3

Second Row:

• N, J, ?
  • Alphabetically, they are: N (14), J (10), ?
  • The differences: J - N = -4
  • Continuing the pattern of differences: ? should be 10 - 4 = 6, which corresponds to the letter F.

Third Row:

• V, N, M
  • Alphabetically, they are: V (22), N (14), M (13)
  • The differences: N - V = -8, M - N = -1

Conclusion

The most consistent pattern is in the second row, where the difference between the letters appears to be -4. Thus, following this pattern, the missing letter should be F (10 - 4 = 6).

So, the missing letter is F.

Would you like more details or have any questions? Here are some related questions you might find interesting:

1. What is the next letter in the sequence: A, D, G, J, ...?
2. How to find the missing number in a sequence of numbers?
3. What is the pattern in the following letter sequence: B, E, H, K, ...?
4. Can you identify the rule in the sequence: 2, 6, 12, 20, ...?
5. What is the relationship between the letters in the following pairs: (A, C), (B, D), (C, E), ...?

Tip: When solving pattern problems, try to identify consistent differences or relationships between the elements in the sequence.