Work out venn diagram (2 sets) instantly with clear inputs, formula shown and shareable results.
A two-set Venn diagram has four regions: A only, both, B only and neither. Set sizes are recovered by adding the relevant regions, and the union is everything except the outside region.
From regions
|A| = onlyA + both, |A ∪ B| = onlyA + both + onlyB, universe = union + neither
|A| = 40, |B| = 45, the union is 70 and the universe holds 80.
The four regions must add to the total surveyed, and |A| + |B| − |A ∩ B| must equal the union.