A railroad trestle spans a gorge 80 feet wide and connects two cliffs at heights of 112 and 172 feet above the bottom of the gorge. A train is crossing this gorge from the higher cliff to the lower. When the front of the train has traveled 3/4 of the trestle's length, how many feet is it above the bottom of the gorge?
+36916 172 - 112 = 60 feet
Since it is a straight line of constant slope, the train will have dropped 3/4 * 60 = 45 ft from the 172 ft side
172-45 = 127ft above the floor of the gorge.
