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Female soto.a

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Distance, Rate, and Time Reply to this Post
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Deke's boat travels 12km/h in still water. Deke travels 45 km downstream and then returns 45 km upstream in a total time of 8 hours. Find the speed of the current. Help anyone?
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Thanks ahead for the help :-)!
[Nov 30, 2010 9:01:43 PM] Show Post Printable Version        Bing [Link] Report threaten post: please login first  Go to top 
Female pskinner

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applause   Re: Distance, Rate, and Time Reply to this Post
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Deke's boat travels 12km/h in still water. Deke travels 45 km downstream and then returns 45 km upstream in a total time of 8 hours. Find the speed of the current. Help anyone?


Let c=speed of current.

d=r*t so, t=d/r

Time upstream +Time downstream = 8:

45/(12+c)+45/(12-c)=8

The rest is algebra: solve and get c=+ or - 3.
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Principal Skinner
[Dec 1, 2010 5:49:42 PM] Show Post Printable Version     [Link] Report threaten post: please login first  Go to top 
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