# Stuck

• December 13th 2008, 12:22 PM
pexler
Stuck
A speedboat takes 3 hours longer to go 60 miles up a river than to return. If the boat cruises at 15 miles per hour in still water, what is the rate of the current?
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• December 13th 2008, 01:22 PM
CaptainBlack
Quote:

Originally Posted by pexler
A speedboat takes 3 hours longer to go 60 miles up a river than to return. If the boat cruises at 15 miles per hour in still water, what is the rate of the current?
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let $x$ be the current speed in miles per hour, then the time (in hous to go upriver is:

$t_1=\frac{60}{15-x}$

and the time to go down river is:

$t_2=\frac{60}{15+x}$

and you are told that $t_1=t_2+3$.

CB