2 trains started toward each other from station 300 miles apart. The eastbound train travels at 35 mph while the westbound train at 40 mph. A magical bird started flying at a speed of 80 mph back and forth between the front of each train as they travel toward each other. How many miles has the bird flown when the two trains pass each other?
It's the same as if one train were stopped and the other train was traveling
toward it at 35+40 or 75 mph. So time = distance/rate = 300/75 = 4 hours.
The bird flies for 4 hours at 40mph and distance = rate × time = 40×4 = 160
miles.
Edwin