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A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?
Answer: Option (A) 230 m Explanation:Relative speed = (120 + 80) km/hr = 200 x (5 /18)m/sec = 500/9 m/sec. Let the length of the other train be x metres. Then, (x + 270)/9 = 500/9 x + 270 = 500 x = 230.
= 200 x (5 /18)m/sec
= 500/9 m/sec.
Let the length of the other train be x metres.
Then, (x + 270)/9 = 500/9
x + 270 = 500
x = 230.
A jogger running at 9 kmph alongside a railway track in 240 metres ahead of the engine of a 120 metres long train running at 45 kmph in the same direction. In how much time will the train pass the jogger?
Answer: Option (C) 36 sec Explanation: Speed of train relative to jogger = (45 - 9) km/hr = 36 km/hr. = 36 x (5 /18)m/sec = 10 m/sec. Distance to be covered = (240 + 120) m = 360 m. Time taken = 360/10 sec = 36 sec.
Answer: Option (C) 36 sec
Explanation:
Speed of train relative to jogger = (45 – 9) km/hr = 36 km/hr.
= 36 x (5 /18)m/sec
= 10 m/sec.
Distance to be covered = (240 + 120) m = 360 m.
Time taken = 360/10 sec = 36 sec.
See lessTwo trains are moving in opposite directions @ 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is:
Answer: Option (C) 48 Explanation: Relative speed = (60+ 90) km/hr = 150 x (5/18) m/sec = 125/3 m/sec. Distance covered = (1.10 + 0.9) km = 2 km = 2000 m. Required time = 2000 x (3/125) sec = 48 sec.
Answer: Option (C) 48
Explanation:
Relative speed = (60+ 90) km/hr
= 150 x (5/18) m/sec
= 125/3 m/sec.
Distance covered = (1.10 + 0.9) km = 2 km = 2000 m.
Required time = 2000 x (3/125) sec = 48 sec.
See lessA train 360 m long is running at a speed of 45 km/hr. In what time will it pass a bridge 140 m long?
Answer: Option (A) 40 sec Explanation: Formula for converting from km/hr to m/s: X km/hr = X x (5/18) m/s. Therefore, Speed = 45 x (5/18) m/sec = 25/2 m/sec. Total distance to be covered = (360 + 140) m = 500 m. Formula for finding Time = Distance/Speed Required time = (500 x 2)/25 sec = 40 sec.
Answer: Option (A) 40 sec
Explanation:
Formula for converting from km/hr to m/s: X km/hr = X x (5/18) m/s.
Therefore, Speed = 45 x (5/18) m/sec = 25/2 m/sec.
Total distance to be covered = (360 + 140) m = 500 m.
Formula for finding Time = Distance/Speed
Required time = (500 x 2)/25 sec = 40 sec.
See lessTwo trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is:
Answer: Option (A) 50 m Explanation: Let the length of each train be x metres. Then, distance covered = 2x metres. Relative speed = (46 - 36) km/hr = 10 x (5 /18)m/sec = 25/9 m/sec 2x/36 = 25/9 2x = 100 x = 50.
Answer: Option (A) 50 m
Explanation:
Let the length of each train be x metres.
Then, distance covered = 2x metres.
Relative speed = (46 – 36) km/hr
= 10 x (5 /18)m/sec
= 25/9 m/sec
2x/36 = 25/9
2x = 100
x = 50.
See lessA train 240 m long passes a pole in 24 seconds. How long will it take to pass a platform 650 m long?
Answer: Option (B) 89 sec Explanation: Speed = (240/24) m/sec = 10 m/sec. Required time = (240 + 650)/10 sec = 89 sec.
Answer: Option (B) 89 sec
See lessExplanation:
Speed = (240/24) m/sec = 10 m/sec.
Required time = (240 + 650)/10 sec = 89 sec.
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) 3 : 2 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. (27x + 17y) /(x+ y)= 23 27x + 17y = 23x + 23y 4x = 6y x /y= 3/2 .
Answer: Option (B) 3 : 2
See lessExplanation:
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.
(27x + 17y) /(x+ y)= 23
27x + 17y = 23x + 23y
4x = 6y
x /y= 3/2 .