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
19purchased romance novels
14 purchased mysteries and science fiction
10 purchased mysteries and romance novels
7 purchased science fiction and romance novels
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?
According to the Venn diagram, the region that represents customers who purchased mysteries but not romance novels has a cardinality of 36 - 10 - 3 = 23. Therefore, 23 customers purchased mysteries but not romance novels.
To find out how many customers purchased mysteries but not romance novels, we need to look at the intersection of the "mysteries" region and the "not romance novels" region in the Venn diagram.
Based on the given information, we know that:
- 36 customers purchased mysteries in total.
- 10 purchased mysteries and romance novels.
- 3 purchased all three types of books.
So, to find the number of customers who purchased mysteries but not romance novels, we can subtract the customers who purchased both mysteries and romance novels (10) and the customers who purchased all three types of books (3) from the total number of customers who purchased mysteries (36):
36 - 10 - 3 = 23
Therefore, 23 customers purchased mysteries but not romance novels.