A driver counts 25 telephone poles in exactly 1 minute along a straight road. Poles are 40 m apart (uniform spacing). At what speed is the car travelling (in km/h)?

Introduction / Context:
When counting poles, the number of intervals is usually one less than the number of poles seen during the timing interval (starting at a pole). Thus, distance ≈ (poles − 1) * spacing. Convert metres per minute to km/h for the final speed.

Given Data / Assumptions:

• Poles counted = 25 in 1 min.
• Spacing = 40 m.
• Assume counting starts at a pole and ends at the 25th pole.

Concept / Approach:
Intervals = 25 − 1 = 24; distance in 1 min = 24 * 40 = 960 m. Convert 960 m/min to km/h by multiplying by 60 and dividing by 1000.

Step-by-Step Solution:

Verification / Alternative check:
Using 25 intervals would yield 60 km/h, but that assumes counting from mid-interval rather than pole-to-pole; the standard interpretation uses intervals.

Why Other Options Are Wrong:
52.4/48.2/44.9 km/h do not align with either interpretation; 57.6 km/h matches the standard pole-interval method.

Common Pitfalls:
Taking 25 intervals instead of 24; mis-converting m/min to km/h.

Final Answer:
57.6 km/h