N = N(M) + N(S) + N(R) - N(M and S) - N(M and R) - N(S and R) + N(M and S and R)
= 36+28+12 - 15 - 12 - 8 + 4
= 45
If the question is, How many did not buy any type of book, then it would be 59-45 or 14
You did not state a question.
You could draw a Venn diagram and all mysteries would be revealed.
A survey of 59 customers was taken at a bookstore regarding the types of books purchased. The survey found 36 customers purchased mysteries, 28 purchased science fiction, 21 purchased romance novels, 15 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
2 answers
32