Multiple choice

Two trains, each of length 125 metre, are running in parallel tracks in opposite directions. One train is running at a speed 65 km/hr and they cross each other in 6 seconds. The speed of the other train is - प्रत्येक 125 मीटर लंबी दो रेलगाड़ियाँ समांतर पटरियों पर विपरीत दिशा में चल रही हैं। उनमें एक रेलगाड़ी 65 किमी./घं. की गति से चल रहीं है और वे दोनों एक-दूसरे को 6 सेकण्ड में पार कर लेती हैं। तदनुसार, दूसरी रेलगाड़ी की गति कितनी होगी?

  1. 75 km/hr/किमी./घं.

  2. 85 km/hr/किमी./घं.

  3. 95 km/hr/किमी./घं.

  4. 105 km/hr/किमी./घं.

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total distance to cross = 125 + 125 = 250m = 0.25 km. Time = 6 seconds = 6/3600 hr = 1/600 hr. Relative speed (opposite directions) = 0.25 ÷ (1/600) = 150 km/hr. Speed of other train = 150 - 65 = 85 km/hr. Option A (75 km/hr) would result from subtracting incorrectly.