SOLUTION: junior's boat will go 15 miles per hour in still water. if he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of th
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-> SOLUTION: junior's boat will go 15 miles per hour in still water. if he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of th
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Question 383989: junior's boat will go 15 miles per hour in still water. if he can go 12 miles downstream in the same amount of time as it takes to go 9 miles upstream, then what is the speed of the current? Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! boat speed in still water = 15 mph
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let current speed be x mph
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speed upstream = 15-x mph
speed downstream = 15+x mph.
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distance downstream = 12 miles
distance upstream = 9 miles
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time downstream = time upstream
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t = d/t
cross multiply
12(15-x)=9(15+x)
180-12x=135+9x
-9x -9x
180-12x-9x=135
-180 -180
-21x=135-180
-21x=-45
/21
x=-45/-21
x= 2.14 mph speed of current
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m.ananth@hotmail.ca
