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Subj:.....Two Hourglasses
          From: LABLaughs.com on 7/6/2002
          (S262b, S643)
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Photo from La Crosse McCormick...

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If you have two hourglasses -- 
one a four-minute timer and the other a seven-minute timer, 
how can you measure nine minutes? 

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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
 
 
Turn over both hourglasses at once. 
When the four-minute hourglass runs out, turn it over. 
When the seven-minute hourglass runs out, turn it over. 
When the four-minute timer runs out this time 
    (eight minutes have elapsed), 
the seven-minute hourglass has been running for one minute. 
Now turn over the seven minute timer back over. 
When the timer runs out, 
nine minutes have elapsed.
 

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