Look at this series: F2, __, D8, C16, B32, ... What term should fill the blank?

Alphanumeric series problems combine two independent patterns running in parallel: one governing the letters and one governing the numbers. Solve each sequence separately using its own consistent rule (here, a constant step on the alphabet position and a constant multiplying factor on the number), then recombine the two results for the missing term.

1. Letters: F, __, D, C, B. Using alphabet positions (F=6, D=4, C=3, B=2), each letter decreases by exactly 1 from the one before it: F(6) -> E(5) -> D(4) -> C(3) -> B(2). So the missing letter is E.

2. Numbers: 2, __, 8, 16, 32. Each number is double the one before it: 2 -> 4 -> 8 -> 16 -> 32. So the missing number is 4.

3. Combining both parallel patterns, the missing term is E4.

Checking consistency: E (position 5) to D (position 4) is a decrease of 1, matching the letter rule; 4 to 8 is a multiplication by 2, matching the number rule. Both checks confirm the term E4.