PLEASE HELP ME OUT I DONT UNDERSTAND

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 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?

From a group of 10 men and 8 women, 5 people are to be selected for a committee so that at least 4 men are on the committee. howmany ways can it be done?

The equation for two lines in the coordinate plane are 2dx+y=4 and -6x+y=3, where d represents an unknown value. what value(s) of d would make these lines parallel?