Question 108461
in a community of 416 people, each person owns a dog or a cat or both. if there are 316 dog owners and 280 cat owners, how many of the dog owners own no cat?
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Draw a Venn diagram of two intersecting circles.  Label it properly and find
that the intersection contains 180 people that have a dog and a cat.
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Formula: 
dog owners + cat owners = 596 
596 - 416 = 180 is the number with both a dog and a cat
180 of the dog owners also have a cat.
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Cheers,
Stan H.