Alphabet Test — “Which letter comes in the middle of the 20th letter from the left and the 21st letter from the right?” (Convert right index first; then find midpoint.)

Introduction / Context:
We mix left and right indexing. Convert the right index to a left index, then take the midpoint of the two left indices.

Given Data / Assumptions:

• 20th from left → T (L=20).
• 21st from right → L = 27 − 21 = 6 → F.

Concept / Approach:
Midpoint index M = (20 + 6)/2 = 13; identify the 13th letter.

Step-by-Step Solution:

Verification / Alternative check:
Alphabet positions A1 … M13 … T20 show M equidistant from F(6) and T(20).

Why Other Options Are Wrong:
They are neighbors of the midpoint or beyond.

Common Pitfalls:
Failing to convert from right before averaging; that yields wrong values.

Final Answer:
M