एक रेलगाड़ी 3750 कि०मी० की दूरी 25 घण्टे में तय करती है, तो एक घण्टे में रेलगाड़ी की औसत तय दूरी कितनी होगी?

Question

एक रेलगाड़ी 3750 कि०मी० की दूरी 25 घण्टे में तय करती है, तो एक घण्टे में रेलगाड़ी की औसत तय दूरी कितनी होगी?

1. A. 140 कि०मी०
2. B. 175 कि०मी०
3. C. 150 कि०मी० (Correct answer)
4. D. 130 कि०मी०

Correct Answer

Option C — 150 कि०मी०

Detailed Solution & Explanation

The correct answer is 150 कि०मी०.

Key Points

• Average speed = total distance ÷ total time = 3750 ÷ 25 = 150 km/h.

Additional Information

• Unit conversions worth memorising: 1 km/h = 5/18 m/s and 1 m/s = 18/5 km/h.
• Average speed is never the plain average of two speeds. For equal *distances* covered at speeds a and b, use the harmonic mean 2ab/(a+b); for equal *times*, the ordinary average (a+b)/2 applies.
• Speed, time and distance questions carry a steady 3-5 marks in HP Patwari — train, boat-and-stream and race problems all reduce to D = S × T.