Question 1056912
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A motorboat goes downstream in a river and covers the distance between two coastal towns in 5 hours. 
It covers this distance upstream in 6 hours. If the speed of the stream is 2 km/h, find the speed of the boat in still water.
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<pre>
Let "u" be the boat speed in still water, in km/h.

Then the boat speed downstream is (u+2) km/h, and the distance downstream is

5*(u+2) kilometers.  (The distance = rate*time, as you know).


The boat speed upstream is (u-2) km/h, and the distance upstream is 

6*(u-2) kilometers.


Since the distance downstream is the same as upstream, you have this equation

5(u+2) = 6(u-2).

Simplify and solve it for "u". You will get the answer u = 22 km/h.


<U>Answer</U>.  The speed of the boat in still water is 22 km/h.
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