Question

    A train can cross a pole in 6 seconds while it can cross

    a 240 metres long platform in 18 seconds. Find the time (in hours) taken by the train to cover a distance of 540 km if the train increased its speed by 50%.
    A 4 hours Correct Answer Incorrect Answer
    B 4.5 hours Correct Answer Incorrect Answer
    C 5 hours Correct Answer Incorrect Answer
    D 5.5 hours Correct Answer Incorrect Answer

    Solution

    Let speed of train is ‘x’ m/s while length of the train is ‘l’ metres.
    So, l = 6x
    And, l + 240 = 18x
    ⇒ 6x + 240 = 18x
    ⇒ 12x = 240
    ⇒ x = 20
    Speed = 20 × 18/5 = 72 km/h
    Increased speed = 1.5 × 72 = 108 km/h
    Time = 540 / 108 = 5 hours

    Practice Next