Trains Problems Questions Answers

• 15. A train is moving at a speed of 132 km/hour. If the length of the train is 110 meters, how long will it take to cross a railway platform 165 meters long.

  1. 7 second
  2. 7.5 second
  3. 8 second
  4. 8.5 second
  5. Only assumption I is implicit
  6. Only assumption II is implicit
  7. Either I or II is implicit
  8. Neither I nor II is implicit
  9. Both I and II are implicit

  Answer :

  Option E

  Explanation:

  As we need to calculate answer in seconds, so first convert speed into meter/sec.
  
  we know 1 km/hr = 1*(5/18) m/sec
  So, Speed = 132* (5/18) = 110/3 m/sec
  
  Distance need to be covered in passing the platform =
  Length of train + length of platform = 110 + 165
  = 275 meters
  
  Time = Distance/Speed
  
  \begin{aligned}
  => Time = 275* \frac{3}{110} = \frac{15}{2} \\
  = 7.5 seconds
  \end{aligned}

• 16. In what time will a train 100 meters long cross an electric pole, if its speed is 144 km/hr

  1. 5 seconds
  2. 4.5 seconds
  3. 3 seconds
  4. 2.5 seconds

  Answer :

  Option D

  Explanation:

  First convert speed into m/sec
  
  Speed = 144*(5/18) = 40 m/sec
  
  Time = Distance/speed
  = 100/40 = 2.5 seconds

• 17. 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 ?

  1. 1:3
  2. 3:2
  3. 3:5
  4. 3:7

  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,
  Length of the second train = 17y metres.
  [because distance = speed*time]
  
  \begin{aligned}
  \frac{27x+17y}{x+y} = 23 \\
  => 27x + 17y = 23x + 23y \\
  => 4x = 6y \\
  => \frac{x}{y} = \frac{6}{4}
  \end{aligned}
  So ratio of the speeds of train is 3:2

• 18. Two trains 140 metre and 160 metre long run at the speed of 60 km/hr and 40 km/hr respectively in opposite direction on parallel tracks. What time these will take to cross each other ?

  1. 10.7 Seconds
  2. 10.8 Seconds
  3. 10.9 Seconds
  4. 11.8 Seconds

  Answer :

  Option B

  Explanation:

  Relative Speed = 60+40 = 100 Kmph
  = 100*(5/18) = 250/9 m/sec
  
  Distance to be covered = 140 + 160 = 300 metres
  
  Time = Distance/Speed
  
  \begin{aligned}
  Time = 300*\frac{9}{250} \\
  = \frac{54}{5} = 10.8\text{ seconds}
  \end{aligned}

• 19. How long does a train 110 meters long running at the speed of 72 km/hour take to cross a bridge 132 meters in length ?

  1. 15 seconds
  2. 12.1 seconds
  3. 10 seconds
  4. 8.1 seconds

  Answer :

  Option B

  Explanation:

  Speed = 72 km/hour = 72*(5/18) m/sec
  = 20 m/sec
  
  Total distance to be covered = 110+132 = 142 meters
  
  Time = Distance/Speed
  = 242/20 = 12.1 seconds

• 20. Speed of a goods train is 72 km/hr. This train crosses a 250 meter platform in 26 seconds. Then find the length of goods train.

  1. 250 meters
  2. 260 meters
  3. 270 meters
  4. 280 meters

  Answer :

  Option C

  Explanation:

  First convert speed from km/hr to m/sec
  
  So, Speed = 72*(5/18) = 20 m/sec
  Time = 26 seconds
  
  Let the length of the train be x meters.
  We know, Distance = Speed*Time.
  [you can remember this formula as remembering DUST = D*ST... Distance=Speed*Time]
  
  x+250 = 20*26
  => x = 270 meters
  
  So length of the goods train is 270 meter

• 21. Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other, is

  1. 9.8 seconds
  2. 10.8 seconds
  3. 11.8 seconds
  4. 12.8 seconds

  Answer :

  Option B

  Explanation:

  Relative Speed = 60+40 = 100 kmph
  = 100*(5/18) = 250/9 m/sec
  
  Distance = 140+160 = 300 meters
  
  Time = Distance/Speed
  
  \begin{aligned}
  300*\frac{9}{250} = \frac{54}{5} \\
  = 10.8 \text{ seconds}
  \end{aligned}
  
  So the time trains will take to cross each other will be 10.8 seconds