Problema Solution
The grade of a highway up a hill is 20%. How much change in horizontal distance is there if the vertical height of the hill is 90 feet?
Answer provided by our tutors
the grade is a ratio of "rise" to "run", in which run is the horizontal distance and rise is the vertical distance
%grade = 100 * (vertical rise distance)/(horizontal distance)
%grade = 20%
vertical rise distance = 90 ft
horizontal distance = ?
horizontal distance = 100 * (vertical rise distance)/%grade
horizontal distance = 100*90/20
horizontal distance = 450 ft