Five buses M, N, O, P, Q are in a front-to-back line on a road. M is at the front; Q is at the back. N stands between M and O; P stands between O and Q. Which bus is exactly in the middle?

Introduction / Context:
We are ordering five distinct buses in a single file with two “between” constraints, then identifying the middle (3rd) bus.

Given Data / Assumptions:

• M at position 1 (front), Q at position 5 (back).
• N between M and O ⇒ M < N < O.
• P between O and Q ⇒ O < P < Q.

Concept / Approach:
Place O at position 3 to allow N before it and P after it while keeping M at 1 and Q at 5.

Step-by-Step Solution:
Positions 1→5: M, N, O, P, Q.The middle bus is O.

Verification / Alternative check:
All constraints are satisfied: N between M and O; P between O and Q.

Why Other Options Are Wrong:
M/N/P are at positions 1/2/4, not the center; “None of these” is unnecessary.

Common Pitfalls:
Placing O too far to an end, which makes one “between” clause impossible.

Final Answer:
O