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Math Help - dont know what to do with this question.

  1. #1
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    dont know what to do with this question.

    A train overtakes two persons who are walking, in the same direction in which the train is going, at speed of 2 km/hr and 4 km/hr and passes them completely in 9 sec and 10 sec respectively. Find the length and speed of train.
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  2. #2
    Member integral's Avatar
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    I hope I am not mistaken but I believe this is unsolvable.


    The answeres would vary depending on the amount of time that has taken place while the two people have been walking (or the distance between them)

    I believe you need the distance between the two people to solve this.

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  3. #3
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    Quote Originally Posted by nanooji View Post
    A train overtakes two persons who are walking, in the same direction in which the train is going, at speed of 2 km/hr and 4 km/hr and passes them completely in 9 sec and 10 sec respectively. Find the length and speed of train.
    2 km/hr = 5/9 m/s

    4 km/hr = 10/9 m/s

    let the train length = L meters

    train speed = v m/s


    rate * time = distance

    (v - 5/9)9 = L

    (v - 10/9)10 = L

    (v - 5/9)9 = (v - 10/9)10

    9v - 5 = 10v - 100/9

    100/9 - 5 = v

    55/9 m/s = v

    22 km/hr = v

    L = 50 m
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