hat fell from a fisherman , whole sailing in a rowing boat , in a river
Source: 1996 Estonia National Olympiad Final Round grade 9 p1
November 4, 2020
algebra
Problem Statement
A fisherman, who was sailing in a rowing boat against the current of the river, had a hat falling from the bow of the boat into the water. After half an hour, the fisherman noticed the loss of his cap and immediately turned back. Find the speed of the river if the fisherman caught up with the cap at a distance of km from the place where it fell into the water (the speed of the river and the movement of the boat relative to the water is considered constant).