Solution to: Rowing Across the RiverCall the requested width of the river r.The first time that Patrick and Eric meet, the total distance which they have traveled together equals the width of the river, or r. The second time that Patrick and Eric meet, the total distance which they have traveled together equals twice the width of the river plus the width of the river, so 3 × r. Because Patrick and Eric row with a constant speed, it also holds that the distance which Patrick traveled in total at the second meeting, equals 3 times the distance which Patrick traveled in total at the first meeting. The distance which Patrick traveled in total at the first meeting is 180. The distance which Patrick traveled in total at the second meeting is r + 100. When we combine the above we get the following equation: 3 × 180 = r + 100.When we solve this equation we find that r = 440.
Therefore, the river is 440 meters wide.
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