A survey of 59 customers was taken at a bookstore regarding

A survey of 59 customers was taken at a bookstore regarding the types of books purchased. The survey found that 36 customers purchased mysteries, 27 purchased science fiction, 20 purchased romance novels, 14 purchased mysteries and science fiction, 11 purchased mysteries and romance novels, 6 purchased science fiction and romance novels and 2 purchased all three types of books

. a) how many customers only purchased romance novels

b) There were how many customers who purchased mysteries and science fiction, but not romance novels

. c) There were how many customers who purchased mysteries or science fiction

d) there were how many customers who purchased mysteries or science fiction, but not romance novels

e) there were how many customers who purchased exactly 2 types of books

Solution

36 customers purchased mysteries, 27 purchased science fiction, 20 purchased romance novels, 14 purchased mysteries and science fiction, 11 purchased mysteries and romance novels, 6 purchased science fiction and romance novels and 2 purchased all three types of books

customers who purchased only romance = 20 - ( mysteries and romance + sci and romaince - all three types )

= 20 - ( 11 + 6- 2) = 15

b) mysteries and sci fi but not romance = customer purchased both mysteries and sci fi - all three

= 14 - 2 = 12

c) customers who purchased mysteries = 36 - ( 14 + 11 - 2) = 13

customers who purchased sci fi = 27 - ( 14 + 6 - 2) = 9

customers who purchased mysteries or sci fi = 13 + 9 = 22