1. 

What should come in the place of question mark (?) in the following alpha numeric series?

9Z-20, 11A-18, 13Y-16, 15B-14, ?

A. 14D-10
B. 16B-12
C. 17X-12
D. 16X-10
E. 17D-10

Answer: Option C

Explanation:

Pattern of the series as shown below

letter-and-symbol-series-logical-reasoning-practice-level---letter-and symbol-series-problems

Hence, the missing term is 17X12.