I need help please! I've been stuck on this question for forever!

An airport in death valley is 60 feet below sea level, and an airplane is flying 2,000 feet above sea level. how many feet must the plane descend in order to land? a. 2060 b. 2000 feet c. 1940 feet d. 1880 feet e.1400 feet will mark as brainliest

Use composition to determine if (x) or h(x) is the inverse of f(x) for the limited domain x2-1.

Reduce fractions expressing probability to lowest terms. in 3,000 repetitions of an experiment, a random event occurred in 500 cases. the expected probability of this event is?