A survey of 60 customers was taken at a
bookstore regarding the types of books purchased. The survey found that 36
customers purchased mysteries, 28
purchased science fiction, 19
purchased romance novels, 14
purchased mysteries and science fiction, 10 purchased mysteries and romance novels, 7 purchased science fiction and romance novels,
and 3 purchased all three types of books.
To figure out how many purchased exactly two types of books Chris made this Venn diagram showing cardinality of each region.
So, how many purchased mysteries but not romance novels?
From the Venn diagram, we can see that the region for mysteries but not romance novels is 36 - 10 - 3 = 23 customers. Therefore, 23 customers purchased mysteries but not romance novels.
To determine how many customers purchased mysteries but not romance novels, we need to look at the region of the Venn diagram representing mysteries only. According to the information given in the survey:
36 customers purchased mysteries.
10 customers purchased mysteries and romance novels.
3 customers purchased all three types of books.
To find the number of customers who purchased mysteries but not romance novels, we need to subtract the customers who purchased both mysteries and romance novels, as well as the customers who purchased all three types of books from the total number of customers who purchased mysteries:
36 - 10 - 3 = 23
Therefore, 23 customers purchased mysteries but not romance novels.