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).
(In reply to
Solution Without Almost No Equations by Gordon Steel)
Actually, Gordon... the boat that went 700 the first time they passed is the slower boat.
At the time of the 2nd passing. The boat in question didn't end up 300 yards short of returning home. It only passed the far side by 300 yards.... He is actually 1500 yards short of returning to the home shore.
But yes... 2100 is 300 yards past one width of the river, and 2100 - 300 = 1800.
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Unfortunately, it is not obvious (at least to me) without setting up the equations, which boat is near which side at the respective meetings.
re: Solution Without Almost No Equations
