66. Highway Engineering Interstate 70 west of Denver, Colorado, has a section posted as a 6% grade. This means that for a horizontal change of 100 ft there is a 6−ft vertical change.
(a) Find the slope of this section of the highway.
(b) On a highway with a 6% grade what is the horizontal distance required to climb 250 ft ?
(c) A sign along the highway says 6% grade for the next 7 mi . Estimate how many feet of vertical change there are along those 7 mi . (There are 5280 ft in 1 mile.)