Question

In a town, 30% of the households own a dog, 20% own a cat, and 10% own both a dog and a cat. If we select a household at random, the chance that they own a dog or a cat is __________.

O 50%.
O 60%.
O 40%.

Answer 1

40%

Explanation:

30% + 20% - 10%

= 40%

Answer 2

40%

Explanation:

A- have a dog

P(A)=30%

B- have a cat

P(B)=20%

Have both pats

P(A&B)=10%

We want to know probability of (A or B), so we have:

P(AorB)=P(A)+P(B)-P(A&B)=30%+20%-10%=40%