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.

A Venn diagram captioned: "In a survey of 250 European travelers, 93 have traveled to Africa, 155 have traveled to Asia, and 70 have traveled to both of these continents, as illustrated in the Venn ...