Finding original position from left in an odd-length row: There are 25 boys in a horizontal row. Rahul is shifted 3 places to his right and then occupies the middle position of the row. What was Rahul's original position from the left end?

Introduction / Context:
Middle-position questions rely on recognizing that in a row of 25, the middle is the 13th position from either end. Shifts then let you back-calculate the original rank.

Given Data / Assumptions:

• Total boys = 25.
• After moving 3 places to the right, Rahul sits at the middle position.

Concept / Approach:
Middle index for odd N is (N + 1) / 2 = 13. If final = original + 3 (to the right), then original = final - 3.

Step-by-Step Solution:

Verification / Alternative check:
Simulate: If Rahul starts at 10th from the left, moving three right lands him at 13th. Correct.

Why Other Options Are Wrong:

• 12th/15th/16th/13th: Do not produce 13th after a +3 shift.

Common Pitfalls:
Thinking the center of 25 is 12th or 12.5th; always use (N+1)/2 for odd N.

Final Answer:
10th