Alphabet series – fill the next three entries Sequence: A, B, N, C, D, O, E, F, P, ?, ?, ?

Introduction / Context:
This sequence interleaves two patterns: a straightforward alphabetical run and a second track that inserts a different letter at every third position. Recognizing the interleaving is the key.

Given Data / Assumptions:

• Given order: A, B, N, C, D, O, E, F, P, ?, ?, ?
• English alphabet, no wrap-around needed.
• We must fill positions 10, 11, and 12.

Concept / Approach:
Look at positions modulo 3. Every third term (3rd, 6th, 9th, …) appears to follow one subsequence, while the non-multiples of three follow another (a simple alphabetical sequence).

Step-by-Step Solution:

Verification / Alternative check:
List the two streams separately: Stream A: A, B, C, D, E, F, G, H; Stream B: N, O, P, Q at positions 3, 6, 9, 12. Merging them matches the original pattern and yields G, H, Q for the last three slots.

Why Other Options Are Wrong:

• G, H, I or G, H, J: the 12th position must continue N→O→P→Q, not I or J.
• J, K, L: ignores the ongoing alphabetical main stream and the special third-position inserts.

Common Pitfalls:
Failing to notice the repeating 1–2–insert rhythm; trying to enforce one uniform rule across all positions.

Final Answer:
G, H, Q