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15.
How long does a train 110 metres long running at the speed of 72 km/hr take to cross a bridge 132 metres in length? [R.R.B. 1998]
Answer & Solution
Answer: (B) 12.1 sec
Solution: Speed of the train = (72 * 5/18) m/sec = 20 m/sec Total distance covered = (110 + 132) m = 242 m. Therefore, Required time = (242/20) sec = 12.1 sec. 
16.
A train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long? [B.S.F. 2001]
Answer & Solution
Answer: (B) 40 sec
Solution: Speed of the train = (45 * 5/18) m/sec = 25/2 m/sec. Total difference covered = (360 + 140) m = 500 m. Therefore, Required time = (500 * 2/25) sec = 40 sec.
17.
A train travelling at a speed of 75 mph enters a tunnel 3 ½ miles long. The train is ¼ mile long. How long does it take for the train to pass through the tunnel from the moment the front enters to the moment the rear emerges?
Answer & Solution
Answer: (B) 3 min
Solution: Total distance covered = (7/2 + ¼) miles = 15/4 miles. Time taken = ( 15/(4 * 75)) hrs = 1/20 hrs = [(1/20) * 60] min = 3 min.
18.
A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train? [Bank P.O. 2003]
Answer & Solution
Answer: (D) None of these
Solution: Speed of the train = [60 *( 5/18)] m/sec = (50/3) m/sec. Length of the train = ( Speed * Time) = ((50/3) * 9) m = 150 m.
19.
A train covers a distance of 12km in 10 min. If it takes 6 seconds to pass a telegraph post, then the length of the train is: [Bank P.O 2000]
Answer & Solution
Answer: (C) 120 m
Solution: Speed of the train = ((12/10) * 60) km/hr =(72 * (5/18)) m/sec = 20 m/sec Length of the train = (Speed * Time) = (20 * 6) m/sec = 120 m 20.
A train covers 240 m long passed a pole in 24 seconds. How long will it take to pass a platform 650 m long? [R.R.B. 1998]
Answer & Solution
Answer: (B) 89 sec
Solution: Speed of the train = (240/24) m/sec = 10 m/sec. Required time = ((240 + 650) / 10) sec = 89 sec.
21.
A train 132 m long passes a telegraph pole in 6 seconds. Find the speed of the train.
Answer & Solution
Answer: (C) 79.2 km/hr
Solution: Speed of the train = (132/6) m/sec = (22 * (18/5)) km/hr 79.2 km/hr
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