Find the missing letters.
R, M, ..., F, D, C

Options

A. F
B. G
C. H
D. I

Answer

To find the missing letter in the series R, M, ..., F, D, C, we can analyze the pattern in the sequence of letters.

1. **Identify the letters and their positions:**
- R is the 18th letter of the alphabet.
- M is the 13th letter of the alphabet.
- F is the 6th letter of the alphabet.
- D is the 4th letter of the alphabet.
- C is the 3rd letter of the alphabet.

2. **Determine the differences between the letters:**
- From R (18) to M (13): 18 - 13 = 5
- From M (13) to the missing letter: Let's denote the missing letter's position as X.
- From the missing letter (X) to F (6): X - 6 = ?
- From F (6) to D (4): 6 - 4 = 2
- From D (4) to C (3): 4 - 3 = 1

3. **Establish a pattern in the differences:**
- The differences we have so far are:
- R to M: -5
- M to the missing letter: ?
- F to D: -2
- D to C: -1
- The differences appear to be decreasing by 1 each time, starting from -5.

4. **Calculate the missing letter's position:**
- If we continue the pattern, the difference from M to the missing letter should be -3 (since -5, -4, -3, -2, -1).
- Therefore, X = 13 - 3 = 10.
- The 10th letter of the alphabet is I.

5. **Conclusion:**
- The missing letter is I.

Thus, the complete series is R, M, I, F, D, C.