What are the next three terms of the following series? K , A , J , B , I , C ,…

Concept: This is an alternating (interleaved) series formed by merging two independent alphabetical sub-series placed at alternating positions — one running backward through the alphabet, the other running forward, each by a fixed one-letter difference.

1. Separate the terms at the odd positions — the first, third, fifth, seventh, and ninth terms of the series: K, J, I, H, ... — each letter is a fixed one-letter difference before the previous one in the alphabet, so continuing after H gives G.

2. Separate the terms at the even positions — the second, fourth, sixth, eighth, and tenth terms of the series: A, B, C, ... — each letter is a fixed one-letter difference after the previous one in the alphabet, so continuing after C gives D, and then E.

3. Reassemble the two sub-series in their original alternating order: the eighth term is D, the ninth term is G, and the tenth term is E.

Cross-check: Converting each letter to its alphabet position confirms this arithmetically — K=11, J=10, I=9, H=8, each one less than the one before, so the next is G=7; A=1, B=2, C=3, each one more than the one before, so the next two are D=4 and E=5. This independently confirms D, G, E.