Apainter is hired to paint the interior walls of a large warehouse. the function f(x)=20,000−40x models the area in square feet that remain to be painted, where x represents the number of minutes the painter has worked from the 100-minute mark through the 200-minute mark of the project. what is the practical range of the function? a) all integers b) all real numbers between 100 and 200 inclusive c) all real numbers between 12,000 and 16,000 inclusive d) integers from 100 to 200 inclusive