In set notation this is B = {1, 4, 9}. 30 people answered a survey about whether they have a dog or a cat. The Venn diagram shows the information from the survey. 13 people have got a dog.

This app displays an intricate Venn diagram, containing various combinations of set intersections, unions and complements. Users can shade the area they choose by clicking on the diagram. Users can ...

One of Venn’s major achievements was to find a way to visualise a mathematical area called set theory ... s include probability theory and symbolic logic. Venn had initially used diagrams ...