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Thread: Rope burns

  1. #1
    Platinum Lounger
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    Rope burns

    You have 2 lengths of rope.
    Each one burns in exactly one hour.
    They are not necessarily of the same length or width as each other.
    The ropes do not burn at a uniform rate thus burning half of the rope is not necessarily 1/2 hour.

    By burning the ropes, how do you measure exactly 45 minutes worth of time?

  2. #2
    Plutonium Lounger Leif's Avatar
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    Re: Rope burns

    <span style="background-color: #FFFF00; color: #000000; font-weight: bold"><font color=yellow>Light one end of rope #1.
    Light both ends of rope #2.
    When rope #2 is fully burnt out (30 mins), light the other end of rope #1.
    Rope #1 will fully burn out after 45 mins.</font color=yellow></span hi>

  3. #3
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    Re: Rope burns

    Tie one end of each of the ropes to the wide hose from <!post=puzzle 390843,390843>puzzle 390843<!/post>. Light the free end. Fill the tank with the small hose. This takes exactly 45 minutes. (You can also use the hourglasses from <!post=puzzle 390924,390924>puzzle 390924<!/post>)

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    Plutonium Lounger Leif's Avatar
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    Re: Rope burns

    <img src=/S/rofl.gif border=0 alt=rofl width=15 height=15>

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    Re: Rope burns

    Hans, I am in awe, a brilliant answer <img src=/S/clapping.gif border=0 alt=clapping width=19 height=23>

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    Re: Rope burns

    Well done Leif, that was the answer I was expecting.

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    5 Star Lounger Ruff_Hi's Avatar
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    Re: Rope burns

    I suppose the "fit the rope to the hose" method also gives you an alarm clock. Set it up, light it up, go and stand a fair distance away and when you see a huge explosion, you'll know that 45 minutes has passed.
    (Location Australia, then UK, but now USA. Heart, outlook, attitude, etc always Australian)
    Quote: "All Happiness is the release of internal pressure"

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