<PRE><B>Question 1054311</B>
I use a step by step logic method
( not the only way to do this )
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12 workers take 15 days to finish 1/3 of a house
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After 1/3 of the house is finished, I want to know
how many workers can finish the remaining 2/3
of the house in 18 aditional days.
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It will take twice as many workers do do twice as 
much work ( 2/3 of a house ) in the same time, so
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24 workers take 15 days to do 2/3 of a house
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If wokers only have 1/5 of this amount of time to do
the same amount of work ( 2/3 of a house ), then
it will take 5 times as many workers, so
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120 workers take 3 days to do 2/3 of a house
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Now if workers can take 6 times as long to do the
same amount of work, then it will only require 1/6
as many workers, so
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20 workers take 18 days to do 2/3 of a house 
( the remaining 2/3 )

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