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Homework Help: A belongs to b, b subset c, a not a subset of c

  1. Sep 5, 2012 #1
    1. The problem statement, all variables and given/known data
    a∈b, b⊆c, a not ⊆ c
    (in other words, the last subset symbol should have a line from top to bottom)

    2. Relevant equations

    3. The attempt at a solution

    ive tried a million things, I cant find anything that doesnt break one of the conditions

    the most recent attempt is that
    A, B and C are all empty sets, but that would imply that a can be an element of B. my logic is that a doesnt contain all the elements of c, because there are no elements of c

    every other thing ive tried has c containing all the elements of B, but since B contains all the elements of A, i run into a logical problem.

    I tried for a long time on this one, and I really need help
  2. jcsd
  3. Sep 5, 2012 #2
    This might be an exercise in understanding what ∈ and ⊆ mean, but I'm not sure if you copied the problem correctly. Are you sure that's what it reads?
  4. Sep 5, 2012 #3


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    Science Advisor

    Consider b= {1, 2, 3}, c= {1, 2, 3, 4}, a= 1.
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