SOLUTION: A boat takes 6
hours to go 30
miles upstream. It can go 72
miles downstream in the same time. Find the rate of the current and the rate of the boat in still water.̴
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-> SOLUTION: A boat takes 6
hours to go 30
miles upstream. It can go 72
miles downstream in the same time. Find the rate of the current and the rate of the boat in still water.̴
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miles downstream in the same time. Find the rate of the current and the rate of the boat in still water. (Hint: Because the current pushes the boat when it is going downstream, the rate of the boat downstream is the sum of the rate of the boat and the rate of the current. The current slows down the boat when it is going upstream, so the rate of the boat upstream is the difference of the rate of the boat and the rate of the current.) Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = speed of boat in still water in mi/hr
Let = speed of current in mi/hr
-----------------------------------------
Going upstream:
(1)
Going downstream:
(2)
----------------------------
(1)
and
(2)
-----------------------
Add the equations
and
(1)
(1)
--------------------
The speed of boat in still water is 8.5 mi/hr
The speed of the current is 3.5 mi/hr
