Data Sufficiency – Linear Arrangement (Middle Position) Question: In a row of five children A, B, C, D, and E, who stands in the middle? Statements: I. D is immediately to the right of E, and B is immediately to the left of E. II. B is at the extreme left end of the row.

Introduction / Context:
Determine the middle position (third from either end) among five children using relative and absolute placement clues. Data Sufficiency focuses on whether the given statements provide enough information to answer uniquely.

Given Data / Assumptions:

• Exactly five positions in a single row.
• I: B is immediately left of E; D is immediately right of E → the trio B-E-D must be consecutive in that exact order.
• II: B is at the extreme left of the row.

Concept / Approach:
Use Statement I to form a rigid consecutive block and Statement II to anchor the block in the row. With five positions, anchoring resolves the middle position uniquely.

Step-by-Step Solution:
From I: consecutive order must be B, E, D. From II: B is at position 1 (leftmost). Therefore positions 1–3 are B–E–D respectively. Hence the middle (position 3) is D, and A, C occupy positions 4 and 5 in some order.

Verification / Alternative check:
I alone: The block B–E–D could be at positions (1–3), (2–4), or (3–5), leading to different middles (D/E/B respectively). Insufficient. II alone: Knowing only B is at the extreme left gives no full order. Insufficient. I + II: Unique placement; sufficient.

Why Other Options Are Wrong:
Any claim that a single statement suffices contradicts the multiple possible placements with I alone and the lack of detail with II alone.

Common Pitfalls:
Misreading 'immediate' as 'somewhere left/right' rather than exactly adjacent.

Final Answer:
Both I and II are sufficient