All PSAT Math Resources
Example Questions
Example Question #1 : Venn Diagrams
Giving the Venn diagram above, what is the sum of the numbers in the set ?
The notation stands for "A union C," which refers to everything that is in either set or set .
When we add the numbers together, we get:
Example Question #11 : Venn Diagrams
In a class of senior high-school students, have pet cats, have pet dogs, have both cats and dogs, and have neither cats nor dogs. How many total students are in the class?
A Venn diagram can help us determine the total number of students in the class.
First, we must calculate the number of students who have ONLY cats or ONLY dogs. First, for cats, 15 students have cats, and 5 students have both cats and dogs.
Ten students have only cats.
For dogs, 12 students have dogs, and 5 students have both cats and dogs.
Seven students have only dogs.
Using this information, we can fill in the Venn diagram.
This diagram shows the 10 students with only cats, the 7 students with only dogs, the 5 students with both, and the 8 students with neither. Adding up the numbers will give us the total number of students.
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