SOLUTION: 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 0.1

Algebra ->  Probability-and-statistics -> SOLUTION: 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 0.1      Log On


   

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?
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
P(A or B) = P(A) + P(B) - P(A and B)
P(Dog 0r Cat) = .4 + .3 - .15 = .55