The mean of nine numbers is 6. If two of the numbers are removed, the mean of the seven numbers is still 6. One of the numbers is 4 more than the other number. Find the greater Unknown Number. Show Your work.

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?

Pls brainliest will be awarded if answer is correct

Susie wants to take her friend out for lunch. she wants to spend $9.75 each person. how much will she spend in all.