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  • PUZZLE
    ---------
    John walk upwards on an escalator, with a speed of 1 step per second. After 50 steps, he was at the end. He turned around and ran downwards with a speed of 5 steps per second. After 125 steps, he returned at the beginning of the escalator.

    Can you help John finding out how many steps he needed if the escalator would have stood still?

    a)125
    b)100
    c)200
    d)none

    stay tuned for more puzzles in future..
    Replies
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Replies

  • Anoop Kumar

    Member • Jan 8, 2014

    125
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  • micheal john

    Member • Jan 8, 2014

    none
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  • Rajni Jain

    Member • Jan 8, 2014

    b) 100 is correct answer.
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  • Anoop Kumar

    Member • Jan 8, 2014

    Rajni Jain
    b) 100 is correct answer.
    Explanation please, I think equation should be.
    50/(x-1) = 125/(5-x) where x is speed of elevator.
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  • Rajni Jain

    Member • Jan 8, 2014

    Upwards (along with the escalator), you walk 1 step per second. You need 50 steps, so that takes 50 seconds. This gives the following equation:

    L steps - 50 seconds × v steps/second = 50 steps.
    Downwards (against the direction of the escalator), you walk 5 steps per second. You need 125 steps, so that takes 25 seconds. This gives the following equation:

    L steps + 25 seconds × v steps/second = 125 steps.
    From the two equations follows: L = 100, v = 1. When the escalator stands still, you need 100 steps.

    ​
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  • Dave Jenkins

    Member • Dec 29, 2015

    Can you explain how you arrive at the following conclusion from the two equations 'From the two equations follows: L = 100, v = 1. When the escalator stands still, you need 100 steps.' please.
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  • Vidyut_Vikas

    Member • Jan 21, 2016

    Rajni Jain
    PUZZLE
    ---------
    John walk upwards on an escalator, with a speed of 1 step per second. After 50 steps, he was at the end. He turned around and ran downwards with a speed of 5 steps per second. After 125 steps, he returned at the beginning of the escalator.

    Can you help John finding out how many steps he needed if the escalator would have stood still?

    a)125
    b)100
    c)200
    d)none

    stay tuned for more puzzles in future..
    100 steps.. the ans is b)
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    Cancel
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