In the word "DOCUMENTATION", the positions of certain letters are changed as follows: the third and tenth letters are interchanged, the fourth and seventh letters are interchanged, and the second and sixth letters are interchanged. After performing all these swaps, which letter will be the eleventh letter from the right end of the new arrangement?

Introduction / Context:
This question on letter arrangement involves specific position based swaps within the longer word "DOCUMENTATION". After making all the given interchanges, you must find the letter that stands at a particular position from the right. Such puzzles check your ability to follow multi step instructions without losing track of intermediate changes.

Given Data / Assumptions:
• The original word is "DOCUMENTATION".
• Swaps to be made are: third with tenth letter, fourth with seventh letter, and second with sixth letter.
• After these swaps, we must find the eleventh letter counted from the right in the resulting word.

Concept / Approach:
Because the swaps involve specific positions, the safest method is to index each letter and perform the swaps in a controlled way. Once the final arrangement is known, we can convert the position from the right to the equivalent position from the left by using the length of the word. Remember that for a word of length n, the kth from the right is the (n - k + 1)th from the left.

Step-by-Step Solution:
Step 1: Write "DOCUMENTATION" with positions: 1 D, 2 O, 3 C, 4 U, 5 M, 6 E, 7 N, 8 T, 9 A, 10 T, 11 I, 12 O, 13 N.Step 2: Swap the third and tenth letters. Positions 3 and 10 are C and T. After swapping, we have T at position 3 and C at position 10.Step 3: Swap the fourth and seventh letters. Positions 4 and 7 are U and N. After swapping, N goes to position 4 and U goes to position 7.Step 4: Swap the second and sixth letters. Positions 2 and 6 are O and E. After swapping, E goes to position 2 and O goes to position 6.Step 5: Writing the final arrangement after all swaps gives: 1 D, 2 E, 3 T, 4 N, 5 M, 6 O, 7 U, 8 T, 9 A, 10 C, 11 I, 12 O, 13 N. So the new word is "DETNMOUTACION".Step 6: The word has 13 letters. The eleventh letter from the right is the (13 - 11 + 1) = 3rd letter from the left.Step 7: The third letter from the left in the new arrangement is T.

Verification / Alternative check:
We can verify by listing letters from the right. From the right side, the order is N (1st), O (2nd), I (3rd), C (4th), A (5th), T (6th), U (7th), O (8th), M (9th), N (10th), T (11th), E (12th), D (13th). Clearly, the eleventh letter from the right is T, confirming our earlier calculation.

Why Other Options Are Wrong:
• U: U is the seventh letter from the right, not the eleventh.
• C: C is fourth from the right and tenth from the left, so it does not satisfy the required position.
• I: I is the third from the right, not the eleventh.
• N: N appears at several positions but none of them correspond to being eleventh from the right.

Common Pitfalls:
Some candidates accidentally swap letters in the wrong order or overwrite earlier changes while performing later swaps. Others miscalculate the conversion from right side position to left side index. It is important to perform swaps on a fixed list of positions and then separately compute positions from the right after the final arrangement is clear.

Final Answer:
After applying all the given interchanges in "DOCUMENTATION", the eleventh letter from the right in the resulting word is T.