Identifying the Missing Letter in the Series

The question asks to find the missing letter in the alphabetical series: T, R, ?, N, L, J.

Analyzing the Pattern

To find the missing letter, let's examine the relationship between the given letters by looking at their positions in the alphabet:

• T is the 20th letter.
• R is the 18th letter.
• N is the 14th letter.
• L is the 12th letter.
• J is the 10th letter.

Let's observe the difference between consecutive known letters:

• T (20) to R (18): The difference is $20 - 18 = 2$.
• N (14) to L (12): The difference is $14 - 12 = 2$.
• L (12) to J (10): The difference is $12 - 10 = 2$.

The pattern shows that each letter is 2 positions before the previous letter in the alphabet (a decreasing sequence with a step of -2).

Calculating the Missing Letter

Applying this pattern to find the missing letter:

1. The letter before the missing one is R (18th position).
2. Subtract 2 from R's position: $18 - 2 = 16$.
3. The 16th letter of the alphabet is P.
4. Let's verify: R (18) $\rightarrow$ P (16) $\rightarrow$ N (14). The difference is consistently -2.

Therefore, the letter P replaces the question mark.

Series Completion

The complete series is: T, R, P, N, L, J.

Represented by positions: 20, 18, 16, 14, 12, 10.