Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Calculating all possible relations of 2 sets?

  1. Apr 30, 2010 #1
    A={1,3,5}
    B={4,6,8,10}
    The set AXB that we have been using had 4096 subsets. Why? Can you find a general procedure for calculating the number of possible relations where there are k ordered pairs available?


    I don't know how to calculate how many relations there are? The only information I have found so far is about simple sets with limited pairs. And they use a formula something like 2n^2.

    I also don't know what 'n' stands for?

    Any help appreciated :)
     
  2. jcsd
  3. Apr 30, 2010 #2

    Mark44

    Staff: Mentor

    I have no doubt that n represents the number of elements in a particular set. Have you seen a formula for the number of subsets in a set with n elements? For example, in the set {1, 2} the subsets are {}, {1}, {2}, and {1, 2}. The empty set and the set itself are always subsets of a given set.

    How many elements are in the set A X B?
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook