In the word "DEPRESSION", the first and second letters are interchanged, the third and fourth letters are interchanged, the fifth and sixth letters are interchanged, and so on for each pair. After all such adjacent swaps, which letter will be the seventh letter from the right end of the new arrangement?

Introduction / Context:
This question combines word manipulation with position counting. You must perform systematic pairwise swaps of letters in the word "DEPRESSION" and then identify the letter at a specified position from the right side. These kinds of problems test attention to detail and your ability to follow a structured transformation before counting positions.

Given Data / Assumptions:
• The original word is "DEPRESSION".
• We interchange letters in adjacent pairs: positions (1,2), (3,4), (5,6), (7,8) and (9,10).
• The length of the word is ten letters, so all letters participate in a pair.
• After forming the new word through these swaps, we must find the seventh letter from the right end.

Concept / Approach:
The problem involves two key concepts: adjacent swapping and position counting from the right. It is safer to work from left to right when computing the new arrangement, and then convert the requested right side position into the corresponding left side index. The seventh from the right in a ten letter word is the fourth from the left, because position from left equals total length minus position from right plus one.

Step-by-Step Solution:
Step 1: Write the original word with index positions: 1 D, 2 E, 3 P, 4 R, 5 E, 6 S, 7 S, 8 I, 9 O, 10 N.Step 2: Swap positions 1 and 2: E, D, P, R, E, S, S, I, O, N.Step 3: Swap positions 3 and 4: E, D, R, P, E, S, S, I, O, N.Step 4: Swap positions 5 and 6: E, D, R, P, S, E, S, I, O, N.Step 5: Swap positions 7 and 8: E, D, R, P, S, E, I, S, O, N.Step 6: Swap positions 9 and 10: E, D, R, P, S, E, I, S, N, O. The final word is "EDRPSEISNO".Step 7: We require the seventh letter from the right. The word has 10 letters, so position from left = 10 - 7 + 1 = 4. The fourth letter from the left in "EDRPSEISNO" is P.

Verification / Alternative check:
An alternative is to list the letters from the right after forming the new word. Starting from the right, the letters are O (1st), N (2nd), S (3rd), I (4th), E (5th), S (6th), P (7th), R (8th), D (9th), E (10th). Clearly, the seventh letter in this right side count is P, confirming the previous computation.

Why Other Options Are Wrong:
• R: R is the fourth from the right and eighth from the left in the new word, so it does not match the requested seventh from the right position.
• O: O becomes the first letter from the right, so it lies at the extreme end rather than at the seventh place.
• S: Two S letters appear, but neither occupies the seventh from right position; they are located closer to the middle.
• D: D appears at the second position from the left and therefore is the ninth from the right, which is not the required position.

Common Pitfalls:
Students frequently miscount the pairings or forget one of the swaps. Another very common mistake is to treat seventh from the right as seventh from the left, which leads to a completely different letter. Always remember to convert positions carefully when counting from the right by using the relation left index = total length minus right index plus one.

Final Answer:
After performing all the adjacent swaps, the seventh letter from the right end of the new arrangement is P.