The time between arrivals of small aircraft at a county airport is exponentially distributed with a mean of one hour. Round the answers to 3 decimal places. a) What is the probability that more than three aircraft arrive within an hour? b) If 30 separate one-hour intervals are chosen, what is the probability that no interval contains more than three arrivals? c) Determine the length of an interval of time (in hours) such that the probability that no arrivals occur during the interval is 0.21.

Factor the monomial completely 42a3b3

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?

Harry and jay are both flying on the same plane with an airline that randomly assigns seats to passengers. of the 182 total seats on the plane, 62 are window seats, 58 are middle seats, and the rest are aisle seats. what is the approximate probability that both harry and jay will be assigned aisle seats on the same plane? a. 11.48% b. 3.3% c. 2.08% d. 26.26%