If the series 7, 3, 9, 7, 0, 3, 8, 4, 6, 2, 1, 0, 5, 11, 13 is written in reverse order, which number will be fourth to the right of the seventh number from the left in the reversed series?

Introduction / Context:
This question tests your ability to handle positions in a sequence after reversing its order. Reversing a series flips the positions of all elements, and then you must apply positional instructions like “seventh from the left” and “fourth to the right.” Careful indexing is essential to avoid confusion once the series has been reversed.

Given Data / Assumptions:
- Original series: 7, 3, 9, 7, 0, 3, 8, 4, 6, 2, 1, 0, 5, 11, 13. - The series is to be written in reverse order. - In the reversed series, we must find the seventh number from the left. - Then we must locate the number that is fourth to the right of this seventh number.

Concept / Approach:
First, construct the reversed series by writing the numbers from last to first. Once we have the reversed sequence, we treat it as a fresh series and label positions from the left starting at 1. Identify the seventh element from the left, then move four positions to the right (increasing the index by four) to locate the required element. No additional pattern recognition is needed; only careful positional counting is required.

Step-by-Step Solution:
Step 1: Write the original series: 7, 3, 9, 7, 0, 3, 8, 4, 6, 2, 1, 0, 5, 11, 13. Step 2: Reverse it by writing from last to first: 13, 11, 5, 0, 1, 2, 6, 4, 8, 3, 0, 7, 9, 3, 7. Step 3: Label positions in the reversed series from the left: 1: 13, 2: 11, 3: 5, 4: 0, 5: 1, 6: 2, 7: 6, 8: 4, 9: 8, 10: 3, 11: 0, 12: 7, 13: 9, 14: 3, 15: 7. Step 4: Identify the seventh number from the left. From the list, position 7 holds the number 6. Step 5: Now move four positions to the right of position 7. That means we go to position 7 + 4 = 11. Step 6: At position 11 in the reversed series, the number is 0. Step 7: Therefore, the number that is fourth to the right of the seventh from the left is 0.

Verification / Alternative check:
To verify, you can re write the reversed series in a table and mark the seventh element and then count four steps to the right. Starting at position 7 (6), the positions 8, 9, 10, and 11 contain 4, 8, 3, and 0 respectively. The last in this list is indeed at position 11 and is 0. This reconfirmation ensures that there was no miscount in the initial pass.

Why Other Options Are Wrong:
5: This number appears at position 3 in the reversed sequence, not at the specified relative position. 11: This is at position 2 from the left, again not fourth to the right of the seventh element. 9: This appears at position 13, which is two places to the right of 11 and not the desired position.

Common Pitfalls:
A common error is to try to apply the “seventh from the left” and “fourth to the right” instructions to the original sequence without actually reversing it. Another mistake is mis counting positions after reversal, especially when switching back and forth between the two orders in your head. Writing down the reversed sequence and indexing it explicitly is the safest strategy.

Final Answer:
In the reversed series, the number that is fourth to the right of the seventh number from the left is 0.