Question

    250 metre long train ‘A’ is running with a speed of

    90 km/hr. Train ‘B’ which is 300 metre long is running with a speed of 90 km/h in opposite direction of train ‘A’. For how much time, the smaller train is completely obscured by the larger train when they cross each other?
    A 1 second Correct Answer Incorrect Answer
    B 2 second Correct Answer Incorrect Answer
    C 3 second Correct Answer Incorrect Answer
    D 4 second Correct Answer Incorrect Answer
    E 5 second Correct Answer Incorrect Answer

    Solution

    Length of smaller train = 250 metre Speed of smaller train = 90 × (5/18) = 25 m/s Length of bigger train = 300 metres Speed of bigger train = 90 × (5/18) = 25 m/s Since, the smaller train is completely obscured by larger train, therefore, extra length of larger train = 300 – 250 = 50 metres Relative speed of trains ‘A’ and ‘B ‘= 25 + 25 = 50 m/s (Since, the trains are running in opposite direction) Required time = 50/50 = 1 second

    Practice Next