Question 139288: Can someone help us with this problem? We are working on it in a group and all go a different answer, so we would like to know who got the right answer if any of us, thanks.
The problem is:
Of the 23 homes in a subdivision, 7 need roofing and 5 need landscaping. If two homes need both roofing and landscaping, how many need neither?
The different answers we got were 11 homes, 9 homes 7 homes and 5 homes have no idea where that one came from. Thanks for the help.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Of the 23 homes in a subdivision, 7 need roofing and 5 need landscaping. If two homes need both roofing and landscaping, how many need neither?
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Draw two intersecting circles called roofing and landscaping.
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put "2" in the overlapping area.
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Then there must be another 5 in roofing but not in the overlap.
Also, there must be 3 in landscaping that are not in the overlap.
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Count the number of houses in the circles: 3+2+5 = 10
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There are 23-10= 13 houses that need neither roofing nor landscaping.
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Cheers,
Stan H.
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