In the letter series T, Q, N, K, H, E, B, Y, V, S, P, ?, ?, ?, which three letters should replace the question marks to complete the pattern?

Introduction / Context:
This question gives a long single letter series: T, Q, N, K, H, E, B, Y, V, S, P, ?, ?, ?, and asks you to choose the correct group of three letters that should replace the question marks. The pattern is not immediately obvious, but once you translate letters to their positions and look at the differences, a very simple rule appears.

Given Data / Assumptions:

• Known part of the series: T, Q, N, K, H, E, B, Y, V, S, P.
• Three letters are missing at the end.
• Alphabet positions A 1 to Z 26 are used.
• The same step size is expected between consecutive letters throughout the series.

Concept / Approach:
Because the series alternates between letters that move backwards in the alphabet and also wraps around from B to Y, it is natural to suspect a fixed negative step. By converting each letter to its numeric position and computing consecutive differences, we can detect that the step size is constant. Then we extend the progression by three more steps to get the missing letters and choose the option that matches exactly.

Step-by-Step Solution:
Step 1: Convert each known letter to its alphabet position: T 20, Q 17, N 14, K 11, H 8, E 5, B 2, Y 25, V 22, S 19, P 16. Step 2: Compute the differences: 20 to 17 is minus 3, 17 to 14 is minus 3, 14 to 11 is minus 3, and so on down to 5 to 2 which is minus 3. Step 3: From B 2 to Y 25 is also minus 3 if we wrap around the alphabet, because 2 minus 3 is minus 1, and adding 26 gives 25. Step 4: Continue checking: 25 to 22 is minus 3, 22 to 19 is minus 3, and 19 to 16 is minus 3. The entire series so far follows a constant step of minus 3. Step 5: To find the next letters after P 16, subtract 3 repeatedly. First: 16 minus 3 equals 13, which is M. Next: 13 minus 3 equals 10, which is J. Next: 10 minus 3 equals 7, which is G. Step 6: Therefore, the three missing letters are M, J, G, in that order, forming MJG.

Verification / Alternative check:
Write the full extended series including the missing letters: T (20), Q (17), N (14), K (11), H (8), E (5), B (2), Y (25), V (22), S (19), P (16), M (13), J (10), G (7). Every consecutive step is minus 3 in positions, respecting wrap around between B and Y. No other triple in the answer choices produces this exact continuation of the minus 3 pattern.

Why Other Options Are Wrong:
NKG would produce letters N (14), K (11), G (7). However, if we add these after P 16, the step from P 16 to N 14 would be minus 2, not minus 3, breaking the pattern. NKI, MJH, and LJG similarly give at least one step that is not minus 3. Only MJG maintains the uniform negative step of 3 each time.

Common Pitfalls:
A frequent mistake is to focus only on a part of the series, for example T, Q, N, K, and conclude that the pattern is simply stepping backward by 3, then think that the wrap around from B to Y is an exception. In reality the same minus 3 rule applies across the wrap. Another pitfall is to search for alternating or more complicated patterns before checking for a simple constant difference. Always convert letters into numbers and compute differences first.

Final Answer:
The three missing letters that complete the series are MJG.