私を助けてください私はあなたが方程式を解くことをお願いします

aka help me please i beg you solve the equations

Ill mark the brainliest if you me with the these three questions 7,8,9

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?

45% of the trees in a park are apple trees. there are 27 apple trees in the park. how many trees are in the park in all?