In three sets Q, R and S, the following conditions are found.
In Q ∩ R there are 9 elements.
In Q ∩ S there are 4 elements.
In R ∩ S there are 11 elements.
If (Q ∩ R) ∪ (Q ∩ S) ∪ (R ∩ S) includes 18 elements, how many elements are in Q ∩ R ∩ S?
Thanks for viewing my problem.
(Cphill, move your eyes over on this question plz)
Don't know how to solve this one, MG.......maybe someone else does....(sorry !!! )
In Q and R there are 9.
In Q and S there are 4.
In R and S there are 11.
Combined, there are 18 elements, so there are 3 elements that are the same (9+4+11-18)/2.
I find it easier to visualize it through a venn diagram.