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BRAIN TEASER PROBLEM! Please help me!

  1. Sep 19, 2006 #1
    A teacher is sitting at a park and counts all the kids and all the dogs. She comes to a total of 40 head and 100 legs. How many kids and dogs are there?

    There is more than one answer. the first one is 30 kids and 10 dogs.

    Find ONE more answer!

    There is no trick animal (ie: a three legged dog or two headed kid.).

    ---------

    Can anyone figure this out??? I can't. please let me know the answer.
     
  2. jcsd
  3. Sep 19, 2006 #2
    This just leads to two equasions and two unknowns. So mathematically speaking there is one unique solution.
    Please let us know if you find otherwise.
     
  4. Sep 19, 2006 #3

    NateTG

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    Are there any goats?
     
  5. Sep 19, 2006 #4
    mathematically speaking , another answer is not possible , may be some trick is involved
     
  6. Sep 19, 2006 #5
    I will.. I know there is some kind of trick to it... its racking my brain trying to think of it!
     
  7. Sep 19, 2006 #6

    DaveC426913

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    2k+4d=100
    k+d=40

    One answer. This must be a trick question then. Let's see, no trick animals allowed, so it must be a trick to how or what she's counting.
     
  8. Sep 19, 2006 #7
    My solution:
    40 kids, 10 of which are puppies
    EOM
     
  9. Sep 19, 2006 #8

    DaveC426913

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    Is this the problem EXACTLY as given to you?
     
  10. Sep 19, 2006 #9
    The answer is indeed a trick, assuming that:
    1) All "kids" she counts have 2 legs and 1 head
    2) All "dogs" she counts have 4 legs and 1 head
    3) She is not including anything else in her count (IE, only the legs and heads of kids and dogs in the park, and not, say, her own legs and head)
    4) Her count is accurate
    5) "Kids" and "dogs" are constant throughout the problem
    6) Numbers provided are in base 10

    The question is also poorly worded. She is not, in fact, counting "all the kids and all the dogs". She is actually counting all the kids' legs, kids' heads, dogs' legs, and dogs' heads. The fact that she counts "40 head" is assumably just a typo (should be "40 heads", but that's easily forgiveable), and if you're REALLY being persnickity, it should specify that the teacher counts all the heads and legs "in the park", and should ask how many kids and dogs are "in the park", rather than just how many there are.

    My guess is the answer they're looking for is 29 kids and 10 dogs, but she counts her *own* legs and head.

    DaveE
     
  11. Sep 20, 2006 #10
    maybe dogs mean ugly kids?
     
  12. Sep 20, 2006 #11

    DaveC426913

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    I wondered about this too. I tested a scenario based on the premise there were 40 'head of cattle' in the park, but I didn't get sensible results.
     
  13. Sep 20, 2006 #12

    J77

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    What's red and has got two legs?
     
  14. Sep 20, 2006 #13

    DaveC426913

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    You know, nowhere does it say she counted ONLY kids and dogs. Maybe there was a table. Or better yet, something common in a park (that is not an animal) but has both a head and a number of legs...
     
  15. Sep 20, 2006 #14

    DaveC426913

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    I suppose we could be overlooking the obvious:

    There are 10 dogs, 29 kids, 1 teacher.

    40 heads, 100 legs.
     
  16. Sep 21, 2006 #15

    J77

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    No-one wants to know the answer :(

    Half a dog! :biggrin:
     
  17. Oct 5, 2006 #16
    Lol. Its funnier the way I first heard it.

    What has two legs and bleeds?
     
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