Find the missing term (?) in the following alpha-numeric series. A2B, B3D,…

Concept

An alpha-numeric series may interleave independent patterns at each character position. To find a missing term, inspect the first letter, the number, and the last letter as three separate sequences before combining their next values.

Application

1. The first letters are A, B, C, ?, E. Consecutive alphabet positions give the missing first letter D.

2. The numbers are 2, 3, 5, ?, 11. These are consecutive prime numbers, so the missing number is 7.

3. The last letters are B, D, F, ?, J. Advancing two alphabet positions each time gives the missing last letter H.

Cross-check

Placing D7H between C5F and E11J preserves A–B–C–D–E, the primes 2–3–5–7–11, and B–D–F–H–J simultaneously. Therefore, the missing term is D7H.