<PRE><B>Question 392855</B>
A water main for a street is being laid using a particular kind of pipe that comes in either 18ft or 20ft sections. 
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The designer has determined that the water main would require 14 fewer sections of 20 ft pipe than if the 18 ft sections were used.
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Find the total length.
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Let the total length be x ft.
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# of 20 ft sections would be x/20
# of 18 ft sections would be x/18
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Equation:
# of 18 - # of 20 = 14 
x/18 - x/20 = 14
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Multiply thru by 18*20 to get:
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20x - 18x = 14*18*20
2x = 14*18*20
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x = 2520 ft (total length)
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Cheers,
Stan H. </PRE>