<PRE><B>Question 198643</B>
A cruise boat travels 72 miles down stream in two hours and returns upstream in 6 hours. Find the rate of the stream. 
D=RT so R=D/T 72/2=36 72/6=12 36-12=24 (speed of boat on still water?) 
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Going downstream, the speed of the stream is added to the speed of the boat.
Upstream, it&#39;s subtracted.
72 = (b+s)*2
72 = (b-s)*6
b+s = 36
b-s = 12
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2b = 48
b = 24 mph (speed of boat)
s = 12 mph (speed of stream)
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