In the letter pair series AZ, BY, CX, DW, ?, which pair should replace the question mark to continue the pattern?

Introduction / Context:
This question shows a very regular pair series: AZ, BY, CX, DW, ?. You must choose the next pair of letters. This is a typical example where one letter moves forward through the alphabet while the other moves backward, creating a symmetric pattern.

Given Data / Assumptions:

• Pairs: AZ, BY, CX, DW, ?
• Alphabet positions A 1 to Z 26.
• Each pair consists of two letters that appear to move in opposite directions.

Concept / Approach:
We separate the series into two sequences: one for the first letters (A, B, C, D, ?) and one for the second letters (Z, Y, X, W, ?). The first sequence is clearly increasing by 1, while the second sequence is decreasing by 1. Extending both gives the required pair.

Step-by-Step Solution:
Step 1: Consider the first letters: A, B, C, D. Step 2: Positions are 1, 2, 3, 4, which increase by 1 each time. Step 3: The next first letter should be 4 plus 1 equals 5, which is E. Step 4: Now consider the second letters: Z, Y, X, W. Step 5: Positions are 26, 25, 24, 23, which decrease by 1 each time. Step 6: The next second letter should be 23 minus 1 equals 22, which is V. Step 7: Combine the two results to get the next pair: EV.

Verification / Alternative check:
We can see the series as matching pairs from opposite ends of the alphabet: A with Z, B with Y, C with X, D with W, and then E with V. This is symmetric around the middle of the alphabet. No other candidate pair in the options maintains both the forward sequence for the first letters and the backward sequence for the second letters.

Why Other Options Are Wrong:
EU has the correct first letter E but the second letter U corresponds to position 21, which would break the step of minus 1 from W 23. FW and GV change both letters or step sizes, so they no longer follow the simple plus 1 and minus 1 pattern. EV alone is consistent with both directions of movement.

Common Pitfalls:
Some candidates only notice that the first letters go A, B, C, D, and immediately choose a pair starting with E without checking the second letters. Others may guess based on rough visual symmetry without verifying positions. For alphabet series, it is always safer to convert letters to their positions and check the numerical pattern carefully.

Final Answer:
The pair that correctly continues the series is EV.