m/sec| 2. | A train 125 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is: | |||||||||||||||||||||||||
Answer: Option B Explanation:
= 45 km/hr. Let the speed of the train be x km/hr. Then, relative speed = (x – 5) km/hr.
|
x – 5 = 45 
x = 50 km/hr.| 3. | The length of the bridge, which a train 130 metres long and travelling at 45 km/hr can cross in 30 seconds, is: | ||||||||||||||||||||||||
Answer: Option C Explanation:
Time = 30 sec. Let the length of bridge be x metres.
|
| 4. | Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is: | ||||||||||||||||||
Answer: Option B Explanation:
Let the speeds of the two trains be x m/sec and y m/sec respectively. Then, length of the first train = 27x metres, and length of the second train = 17y metres.
|
| 5. | A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform? | |||||||||||||||||
Answer: Option B Explanation:
Length of the train = (15 x 20)m = 300 m. Let the length of the platform be x metres.
|