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Homework Help: Sets and Relations - quick one

  1. Oct 27, 2005 #1
    If A is the set of even integers and B the set of integers which are multiples of 3, describe the set (AUB) - (AnB) ?

    Basically the answer only requires words, no Venn diagram or the lot.

    So I just put in words .... it's the set which comprises of the even integers OR the odd integer which a multiples of 3 but not both.

    or should I say... it's the set of even integers and multiples of three minus the set of even multiples of three.

    Which is the correct answer please anyone?
  2. jcsd
  3. Oct 27, 2005 #2
    The form of your first answer is better for homework (assuming you mean odd multiples of 3), as it shows a more concrete understanding of the terminology, but it's not correct. the second answer is correct, but doesn't show that you understand the undelying set. It is the set that contains only even integers and odd multiples of 3.
  4. Oct 28, 2005 #3


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    AUB consists of numbers that are even or multiples of 3 (or both).
    AnB consists of numbers that are multiples of 2 and 3: in other words multiples of 6.

    (AUB) - (AnB) consists of all numbers that are multiples of 2 or 3 but not both.
  5. Oct 28, 2005 #4


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    Please don't multiple post.
  6. Oct 29, 2005 #5
    Integers not numbers HallSoftIvy!
  7. Oct 30, 2005 #6


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    How many non-integer numbers are multiples of 3? :devil:
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