document.write( "Question 930479: In a large city, the proportion of households having a dog is 0.4. The proportion of households having a cat is 0.3. The proportion of households having both a dog and a cat is 0.15. What is the proportion of households has only a dog or a cat? \n" ); document.write( "
Algebra.Com's Answer #565091 by ewatrrr(24785)\"\" \"About 
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P(A or B) = P(A) + P(B) - P(A and B)
\n" ); document.write( "P(Dog 0r Cat) = .4 + .3 - .15 = .55
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