Using proportions, it is found that the boat can go 6 m/s in still water.
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
In this problem, we have that:
He goes twice as fast down the river, hence:
v + 2 = 2(v - 2).
v + 2 = 2v - 4
2v - v = 2 + 4
v = 6.
The boat can go 6 m/s in still water.
More can be learned about proportions at https://brainly.com/question/24372153
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