<PRE><B>Question 377692</B>
A woman is paddling a canoe up the creek.  As she passes under a bridge, a can falls out of the canoe.  20 minutes later the woman notices the can missing and she paddles back to get it.  She catches up with the can 1 mile downstream from the bridge.  How fast is the current moving? 
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You can do a lot of math backflips trying to solve this, but if you use the right perspective, it&#39;s easy.
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Consider rather than a creek, that this happens in open water.
It takes the same amount of time paddling back to the can as was spent paddling away from it, a total of 40 minutes.
In 40 minutes, the can moves 1 mile.
1 mile / (2/3 hr) = 1.5 mph
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Remember that all motion is relative, and select your frame of reference accordingly.
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