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 Subj:.....Hat In The River (S255, S653)            From: LABLaughs.com on 12/17/2001    Photo from DailyCal.org...
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The Harvard bridge and the Longfellow bridge are 1 mile
apart.  The MIT crew team starts rowing upstream at the
Longfellow.  As the crew passes under the Harvard, the
coxswain's hat falls into the river.  10 minutes later, the
coxswain notices and turns the boat around instantaneously
and has the crew go back to get it, rowing at the same
constant rate.  By the time the team reaches the hat, they
are back at the Longfellow.  How fast is the river flowing?

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 Finger pointing down from darrell94590 on 1/2/2006
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 Drawing from Ripleys-Believe It Or Not
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THE SOLUTION

Since the crew's speed is measured relative to the river and
the hat is floating on the river, the time it takes the crew
to get back to the hat is also 10 minutes. So, in 20 minutes
the hat travelled 1 mile down the river. Therefore the river's
speed is 1 mile/20 minutes or 3 miles per hour.

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