Heroes never panic.

Logic fun

Posted: November 23rd, 2006 | Author: klaut | Filed under: General | Tags: , | 10 Comments »

Ok, here’s one for you :)

You have two badly-woven ropes with fluctuating widths, but which you know take one hour each to burn completely. But because of their fluctuating widths, thicker parts take longer to burn, so half of each rope may take longer or shorter than 30 minutes to burn. Using these two ropes, how can you time 45 minutes?

10 Comments on “Logic fun”

  1. 1 Keith Peters said at 12:07 am on November 24th, 2006:

    First, what the heck is a tope?

    Took me a couple false starts, but…

    Whatever they are, light one at one end, and the other at both ends.

    When the double burning one is gone, that’s 30 minutes. The other one has 30 minutes left. Light the other end of that. When it’s gone, that’s 45 mins.

  2. 2 klaut said at 6:37 am on November 24th, 2006:

    oops, that is a typo :D … tope = rope ;)
    (fixed now)

    well done, keith … it took me a while to get to the same answer as well :D

  3. 3 mairas said at 10:37 pm on December 1st, 2006:

    But why would you want to burn a perfectly good rope?

  4. 4 klaut said at 4:09 pm on December 2nd, 2006:

    uhm, … maybe … your watch died and you absolutely have to be to some place in 45 minutes because it is a matter of life and death and you just remembered the last MacGyver episode when he used that exact same trick? :) )

  5. 5 mairas said at 1:03 pm on December 4th, 2006:

    Besides, how on earth can you know beforehand that the ropes will burn for one hour? By their weight? And in any case, walking around with a piece of burning rope to get somewhere in time will arouse at least some suspicions.

    I don’t appreciate this riddle at all. I’d rather build a frigging sundial and use the ropes to make some decorative items.

  6. 6 klaut said at 2:02 pm on December 4th, 2006:

    well, you know the exact time the ropes will burn because you read the manual that came with them, right? … what? you tell me you never read manuals that come with stuff you buy? .. doh! :)

    besides, building a sundial would definitely take you more than 45 minutes .. unless you are MacGyver … and you happen to have a chewingum with you … and some sun-glasses

  7. 7 mairas said at 1:40 pm on December 7th, 2006:

    My watch just died today.

  8. 8 klaut said at 3:32 pm on December 7th, 2006:

    i think i might have some spare ropes. Just say a word and they are yours ;)

  9. 9 Angryblue said at 5:17 am on January 17th, 2007:

    you need to put your illustrations up, girl!

  10. 10 klaut said at 8:09 am on January 17th, 2007:

    omg, Justin?! :)
    It has been so long since i last read you! .. Nice to see you are still alive and kicking ;)

    Yeah, i do need to finish a lot of stuff around here :|

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