Problem on Trains


  1. Two trains 70 m and 80 m long respectively, run at the rates of 68 km and 40 km an hour respectively, on parallel rails in opposite directions. How long do they take to pass each other ?









  1. View Hint View Answer Discuss in Forum

    Total distance = 70 + 80 = 150 m
    Relative speed = 68 + 40 = 108 kmph = 108 x (5/18) = 30 m/s

    Correct Option: A

    Total distance = 70 + 80 = 150 m
    Relative speed = 68 + 40 = 108 kmph = 108 x (5/18) = 30 m/s
    So time taken = 150 / 30 = 5 seconds.


  1. A person see a train passing over 1 km long bridge. The length of the train is half that of bridge. If the train clears the bridge in 2 minutes the speed of the train is ?









  1. View Hint View Answer Discuss in Forum

    Distance covered in 2/60 hours = (1 + 1/2) = 3/2 km

    Correct Option: B

    Distance covered in 2/60 hours = (1 + 1/2) = 3/2 km
    Distance covered in 1 hour = (3/2) x (60/2) = 45 km
    So, speed of the train = 45 km/hr



  1. A train 50 meters long passes a platform 100 m long in 10 second. The speed of the train is ?









  1. View Hint View Answer Discuss in Forum

    Distance covered by train in 10 sec = (50 + 100) = 150 m

    Correct Option: C

    Distance covered by train in 10 sec = (50 + 100) = 150 m
    ∴ Speed = 150/10 m/sec = 15 x (18/5) = 54 km/hr


  1. A train covers 90 m in passing a standing man. Find the length of the train.









  1. View Hint View Answer Discuss in Forum

    We know that, the distance covered by a train in passing a pole or a standing man or a signal post or any other object (of negligible length) is equal to the length of the train.

    Correct Option: D

    We know that, the distance covered by a train in passing a pole or a standing man or a signal post or any other object (of negligible length) is equal to the length of the train.

    In this case, train covers 90 m to cross a standing man.
    ∴ Length of the train = 90 m



  1. A 220 m long train passes a signal post in 12 s. Find the speed f the train.?









  1. View Hint View Answer Discuss in Forum

    We know that,
    Speed = Distance/ Time

    Correct Option: C

    We know that,
    Speed = Distance/ Time
    Speed of the train = 220/12 x (18/5) km/h