Q:

A survey of 64 customers was taken at a bookstore regarding the types of books purchased. The survey found that 37 customers purchased mysteries​, 30 purchased science fiction​, 23 purchased romance novels​, 16 purchased mysteries and science fiction​, 12 purchased mysteries and romance novels​, 8 purchased science fiction and romance novels​, and 4 purchased all three types of books.​a) How many of the customers surveyed purchased only mysteries​?​b) How many purchased mysteries and science fiction​, but not romance novels​?​c) How many purchased mysteries or science fiction​?​d) How many purchased mysteries or science fiction​, but not romance novels​?​e) How many purchased exactly two types of​ books?

Accepted Solution

A:
Answer:You need a VENN diagram to answer this question with circles for mysteries, sci fi and romance. They will all intersect and there will be a triple intersection in the middle with "3" Then you work back to the double intersections... subtracting 3 from each of those. To get you started I have 3 in the triple intersection 9 in the M and R intersection, 15 in the M and SF intersection and 6 in the R and SF intersection. Now.. you need to fill in the big circles. For example in the intersections for Mysteries I have 9 + 3 + 6 = 18 I have to subtract that from 42 to get those who just purchased mysteries. You have to do that for the other two circles. Now, add up all the numbers and see if they add to 70, if they don't you have some people outside the diagram that purchased none of them. Once you have your diagram, you can answer your questions and someone here will check your answers.Step-by-step explanation: