Travelling at a speed of 108 km per hour, a train crosses a bridge in 1 minute

Travelling at a speed of 108 km per hour, a train crosses a bridge in 1 minute. If the length of the train is 450 metres, what is the length of the bridge?

  1. 1350 metres
  2. 1200 metres
  3. 1150 metres
  4. 950 metres
Anurag Mishra Professor Asked on 30th April 2016 in Maths.
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  • 1 Answer(s)

    Answer: (1) 1350 metres 

    Solution:-
    Let the length of the bridge be X m. 
    The speed of the train = 108 km/hr. 
    speed in m/sec = 108 x 5/18
     = 6 x 5 
     = 30 m/sec 

    A train crosses a bridge in 1 minutes and  length of train is 450 m. 
    Then, (X + 450)/30 = 60 
     By cross multiplication, 
    X + 450 = 60 x 30 
    X = 1800 – 450 
    X  =1350 m 

    Then, the length of the bridge is 1350 m. 

    Hence, the correct answer is option (1) 1350 m. 

    Anurag Mishra Professor Answered on 1st May 2016.
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