Emilio throws a marshmallow into the air from his balcony. the height of the marshmallow (in feet) is represented by the equation h=−16(t−1/4)^2+49, where t is the time (in seconds) after he throws the marshmallow. what is the maximum height of the marshmallow? enter your answer as the correct value, including units, like this: 42 meters be sure to use the correct units from the context of the problem.

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?