Question 105718
Think about this ...
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To cut a log into 4 pieces you need to make 3 cuts as follows:
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xxxxx-cut-xxxxx-cut-xxxxx-cut-xxxxx
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The strings of 5 x's represent the pieces. And the labels "-cut-" show where the cuts
are made. Therefore, with three cuts you create 4 pieces from the log.  Since the total
time of the cuts is 12 seconds, the 3 cuts take 4 seconds each.  
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To cut the log into 5 pieces you need 4 cuts as follows:
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xxxxx-cut-xxxxx-cut-xxxxx-cut-xxxxx-cut-xxxxx
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Since each cut takes 4 seconds, the time for the 4 cuts is 4*4 = 16 seconds.
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Hope this helps you to visualize the problem and see how to get the answer.
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