Quick Solution

To solve this, we first need to construct the final sequence of letters according to the given rules. Then, we can locate the letter at the required position.

1. Constructing the Alphabetical Series

• Step 1: Write the letters from A to M, leaving a single space between each letter.
  A _ B _ C _ D _ E _ F _ G _ H _ I _ J _ K _ L _ M
• Step 2: Fill the empty spaces with the remaining letters, beginning with N. The final letter of the alphabet, Z, is placed at the very end, after M.

Following these rules, the final constructed series is:

A N B O C P D Q E R F S G T H U I V J W K X L Y M Z

2. Finding the Required Letter

1. First, we need to find the 7th letter from the left in our new series.
   Counting from the beginning: A(1), N(2), B(3), O(4), C(5), P(6), D(7).
   The 7th letter is D.
2. Next, we need to find the 3rd letter to the right of D.
   Counting three places after D in the series:
   D → Q (1st) → E (2nd) → R (3rd).

Final Answer: The required letter is R.