How do you solve a four circle venn diagram?
You can't create a Venn diagram with four circles.
Two circles intersect in at most two points, and each
intersection creates one new region. (Going clockwise around the
circle, the curve from each intersection to the next divides an
existing region into two.)
Since the fourth circle intersects the first three in at most 6
places, it creates at most 6 new regions; that's 14 total, but you
need 2^4 = 16 regions to represent all possible relationships
between four sets.
But you can create a Venn diagram for four sets with four
ellipses, because two ellipses can intersect in more than two