U = {1,2,3,4,5,6,7,8,9} A={1,3,5,7,9} B= {1,2,3,4,5} C = {1,2,5,8,9} what is AUB' = . and what does A'n C = and what is A U A'

Question

how do i solve this

Answer 1

By definition of UNION, A U A' is the set of everything in set A OR outside set A--which is U, the universal set of this problem. It is extremely unfortunate that the universal set is named letter U which appears identical to the Union symbol.

 

To resolve A' ∩ C, look for things in set C that are ALSO in A:, so first, A' = (2,4,6,8}.

Final answer: A' ∩ C, = {2, 8}.

 

Now you can do some work: what is B' ?  After you list this, decide what AUB' is by taking anything in B' or in A, or both.

 

Study these so that you become self-reliant.