<PRE><B>Question 630488</B>
It takes 5 people 1 day to build 1/2 a house.
1 person will take 5 times longer to build 1/2 a house, so
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It takes 1 person 5 days to build 1/2 a house
To build 1 house in the same time will take twice as many people, so
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It takes 2 people 5 days to build 1 house
3 times as many people will take 1/3 the time to build 1 house, so
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It takes 6 people 1 and 2/3 days to build 1 house</PRE>