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Speed, Time and Distance related train Questions, answers and explanations 1. A train is running at a speed of 40 km/hr and it crosses a post in 18 seconds. What is the length of the train? A. 190 metres B. 160 metres C. 200 metres D. 120 metres Answer : Option C Explanation : Speed of the train = 40 km/hr = 40000/3600 m/s = 400/36 m/s Time taken to cross = 18 s Distance Covered = speed× time = (400/36)× 18 = 200 m Distance covered is equal to the length of the train = 200 m 2. A train ,130 meters long travels at a speed of 45 km/hr crosses a bridge in 30 seconds. The length of the bridge is A. 270 m B. 245 m C. 235 m D. 220 m Answer : Option B Explanation : Assume the length of the bridge = x meter Total distance covered = 130+x meter total time taken = 30s speed = Total distance covered /total time taken = (130+x)/30 m/s => 45 × (10/36) = (130+x)/30 => 45 × 10 × 30 /36 = 130+x => 45 × 10 × 10 / 12 = 130+x => 15 × 10 × 10 / 4 = 130+x => 15 × 25 = 130+x = 375 => x ...