<PRE><B>Question 470166</B>
ken makes a 4-mile motorboat trip downstream in 20 minutes ( 1/3 hr). The return trip takes 30 minutes (1/2 hr). Find the rate of the boat in still water and the rate of the current
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4 mi/(1/3) hr = 12 mi/hr
4 mi/(1/2) hr = 8 mi/hr
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The boat&#39;s speed is the average = (12 + 8)/2 = 10 mph
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The current is the difference = 12 - 10 = 2 mph

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