Two boats on opposite sides of a river head towards each other at different speeds. When they pass each other the first time they are 700 yards from one shoreline. They continue to the opposite shoreline, turn around, and move towards each other again. When they pass the second time they are 300 yards from the other shoreline.
How wide is the river? (Assume both boats travel at a constant speed and ignore factors such as turn-around time and the current of the river).
Since the boats pass twice, the combined distance of both boats is precisely three times the width of the river. The total distance travelled by the boat that on its first segment went 700 yards from shore is therefore 3 x 700 = 2100. Since he ends up 300 miles short of returning to home shore, the width of the river is 2100 - 300 = 1800. Gordon S.
Solution Without Almost No Equations
